Add comprehensive test suite, fix minor issues, rename function and file names to match approved verbs (#708)

.github/CONTRIBUTING.md

@@ -58,6 +58,25 @@ You can launch the prerelease version of Win11Debloat by running this command:
    .\Win11Debloat.ps1
    ```
 
+### Running Automated Tests
+
+The automated test cases use Pester 5 and do not modify the registry or other
+system state. The optional bootstrap step installs Pester for your user account
+when needed. To run the complete suite:
+
+```powershell
+.\Scripts\Run-Tests.ps1 -Bootstrap
+```
+
+After the initial setup, run the suite with:
+
+```powershell
+.\Scripts\Run-Tests.ps1
+```
+
+GitHub Actions runs the same test command with Windows PowerShell 5.1 for pull
+requests and pushes to `master`.
+
 ## Implementation Guidelines
 
 ### Project Structure
@@ -72,7 +91,7 @@ Win11Debloat/
 │   ├── Get.ps1                  # Script used for the quick launch method to automatically download and run Win11debloat
 │   ├── AppRemoval/              # App package removal logic
 │   ├── CLI/                     # Command-line interface helpers
-│   ├── Features/                # Feature apply/undo logic (e.g. InvokeChanges.ps1, ReplaceStartMenu.ps1)
+│   ├── Features/                # Feature apply/undo logic (e.g. Invoke-Changes.ps1, Replace-StartMenu.ps1)
 │   ├── FileIO/                  # File input/output helpers
 │   ├── GUI/                     # GUI window definitions and logic
 │   ├── Helpers/                 # Shared helper functions
@@ -220,7 +239,7 @@ Windows Registry Editor Version 5.00
 
 #### 1b. Implement the Feature Logic
 
-If your feature requires more than just applying a registry file, add custom logic to the main script in the appropriate section. In most cases this will involve creating a new entry in the `Invoke-FeatureApply` function (in `Scripts/Features/InvokeChanges.ps1`) for your new feature. If your feature also requires custom undo logic (beyond a simple registry file import), add a corresponding entry to the `Invoke-FeatureUndo` function in the same file.
+If your feature requires more than just applying a registry file, add custom logic to the main script in the appropriate section. In most cases this will involve creating a new entry in the `Invoke-FeatureApply` function (in `Scripts/Features/Invoke-Changes.ps1`) for your new feature. If your feature also requires custom undo logic (beyond a simple registry file import), add a corresponding entry to the `Invoke-FeatureUndo` function in the same file.
 
 #### 2. Add Feature to Features.json
 

.github/workflows/tests.yml

@@ -0,0 +1,26 @@
+name: Tests
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  pester:
+    name: Pester (Windows PowerShell 5.1)
+    runs-on: windows-latest
+    timeout-minutes: 15
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Run tests
+        shell: powershell
+        run: ./Scripts/Run-Tests.ps1 -Bootstrap

Scripts/AppRemoval/Get-WingetInstalledApps.ps1

@@ -17,7 +17,7 @@
     PSCustomObject[] with Name and Id properties. Returns $null on
     failure, or an empty array when winget succeeds but lists no apps.
 #>
-function GetInstalledAppsViaWinget {
+function Get-WingetInstalledApps {
     param (
         [int]$TimeOut = 10,
         [switch]$NonBlocking
@@ -107,4 +107,4 @@ function GetInstalledAppsViaWinget {
     else {
         return & $fetchBlock $TimeOut
     }
-}
+}

Scripts/AppRemoval/Invoke-ForceRemoveEdge.ps1

@@ -1,6 +1,8 @@
-# Forcefully removes Microsoft Edge using its uninstaller
-# Credit: Based on work from loadstring1 & ave9858
-function ForceRemoveEdge {
+<#
+    .SYNOPSIS
+        Forcefully uninstalls Microsoft Edge and removes its leftover shortcuts and autostart entries.
+#>
+function Invoke-ForceRemoveEdge {
     Write-Host "> Forcefully uninstalling Microsoft Edge..."
 
     $regView = [Microsoft.Win32.RegistryView]::Registry32
@@ -54,4 +56,4 @@ function ForceRemoveEdge {
     else {
         Write-Host "Unable to forcefully uninstall Microsoft Edge, uninstaller could not be found" -ForegroundColor Red
     }
-}
+}

Scripts/AppRemoval/Remove-SelectedApps.ps1

@@ -14,12 +14,12 @@
     An array of app package identifiers to remove (e.g. 'Microsoft.BingNews').
 
     .EXAMPLE
-    RemoveApps @('Microsoft.BingNews', 'Microsoft.BingWeather')
+    Remove-SelectedApps @('Microsoft.BingNews', 'Microsoft.BingWeather')
 
     .EXAMPLE
-    RemoveApps -appsList (GenerateAppsList)
+    Remove-SelectedApps -appsList (Generate-AppsList)
 #>
-function RemoveApps {
+function Remove-SelectedApps {
     param (
         $appslist
     )
@@ -33,7 +33,7 @@ function RemoveApps {
         return
     }
 
-    $targetUser = GetTargetUserForAppRemoval
+    $targetUser = Get-TargetUserForAppRemoval
     $appCount = @($appsList).Count
     $appIndex = 0
 
@@ -67,7 +67,7 @@ function RemoveApps {
 
     # Check whether any winget-removed apps are still present, and report errors for each one.
     if ($wingetRemovedApps.Count -gt 0) {
-        $postRemovalList = if ($script:WingetInstalled) { GetInstalledAppsViaWinget -TimeOut 10 -NonBlocking } else { $null }
+        $postRemovalList = if ($script:WingetInstalled) { Get-WingetInstalledApps -TimeOut 10 -NonBlocking } else { $null }
         $edgeForceRemoveRequested = $false
 
         foreach ($app in $wingetRemovedApps) {
@@ -116,7 +116,7 @@ function Remove-WinGetApp {
     } -ArgumentList $app
 
     if ($script:Params.ContainsKey("User")) {
-        Write-Host "Adding scheduled task to uninstall $app for user $(GetUserName)..."
+        Write-Host "Adding scheduled task to uninstall $app for user $(Get-UserName)..."
         Set-RunOnceWingetTask -appId $app
     }
     elseif ($script:Params.ContainsKey("Sysprep")) {
@@ -185,7 +185,7 @@ function Remove-AppxApp {
     The package identifier to check (e.g. 'Microsoft.BingNews').
 
     .PARAMETER InstalledList
-    Optional pre-fetched array of winget objects from GetInstalledAppsViaWinget.
+    Optional pre-fetched array of winget objects from Get-WingetInstalledApps.
     When provided, used directly; otherwise a live winget call is made.
 #>
 function Test-AppStillInstalled {
@@ -205,7 +205,7 @@ function Test-AppStillInstalled {
     }
 
     if ($script:WingetInstalled) {
-        $liveList = GetInstalledAppsViaWinget -TimeOut 10 -NonBlocking
+        $liveList = Get-WingetInstalledApps -TimeOut 10 -NonBlocking
         if (Test-AppInWingetList -appId $appId -InstalledList $liveList) {
             return $true
         }
@@ -241,11 +241,12 @@ function Get-AppRemovalMethod {
                 foreach ($appData in $appsJson.Apps) {
                     $rawMethod = $appData.RemovalMethod
                     $method = if ($rawMethod -and $rawMethod -eq 'WinGet') { 'WinGet' } else { 'Appx' }
-                    if ($appData.AppId -is [array]) {
-                        foreach ($id in $appData.AppId) { $script:AppRemovalMethodCache[$id.Trim()] = $method }
-                    }
-                    else {
-                        $script:AppRemovalMethodCache[$appData.AppId.Trim()] = $method
+                    foreach ($id in @($appData.AppId)) {
+                        if ($id -isnot [string]) { continue }
+                        $normalizedId = $id.Trim()
+                        if (-not [string]::IsNullOrWhiteSpace($normalizedId)) {
+                            $script:AppRemovalMethodCache[$normalizedId] = $method
+                        }
                     }
                 }
             }
@@ -276,12 +277,12 @@ function Request-EdgeForceRemove {
         $result = Show-MessageBox -Message 'Unable to uninstall Microsoft Edge via WinGet. Would you like to forcefully uninstall it? NOT RECOMMENDED!' -Title 'Force Uninstall Microsoft Edge?' -Button 'YesNo' -Icon 'Warning'
         if ($result -eq 'Yes') {
             Write-Host ""
-            ForceRemoveEdge
+            Invoke-ForceRemoveEdge
         }
     }
     elseif ($(Read-Host -Prompt "Would you like to forcefully uninstall Microsoft Edge? NOT RECOMMENDED! (y/n)") -eq 'y') {
         Write-Host ""
-        ForceRemoveEdge
+        Invoke-ForceRemoveEdge
     }
 }
 

Scripts/AppRemoval/Test-AppInWingetList.ps1

@@ -12,7 +12,7 @@
     The identifier to search for (e.g. 'Microsoft.Copilot').
 
     .PARAMETER InstalledList
-    An array of PSCustomObject from GetInstalledAppsViaWinget.
+    An array of PSCustomObject from Get-WingetInstalledApps.
 #>
 function Test-AppInWingetList {
     param(

Scripts/CLI/Show-CliAppRemoval.ps1

@@ -1,6 +1,6 @@
 # Shows the CLI app removal menu and prompts the user to select which apps to remove.
-function ShowCLIAppRemoval {
-    PrintHeader "App Removal"
+function Show-CliAppRemoval {
+    Write-CliHeader "App Removal"
 
     Write-Output "> Opening app selection form..."
 
@@ -8,10 +8,10 @@ function ShowCLIAppRemoval {
 
     if ($result -eq $true) {
         Write-Output "You have selected $($script:SelectedApps.Count) apps for removal"
-        AddParameter 'RemoveApps'
-        AddParameter 'Apps' ($script:SelectedApps -join ',')
+        Add-Parameter 'RemoveApps'
+        Add-Parameter 'Apps' ($script:SelectedApps -join ',')
 
-        SaveSettings
+        Save-Settings
 
         # Suppress prompt if Silent parameter was passed
         if (-not $Silent) {
@@ -19,7 +19,7 @@ function ShowCLIAppRemoval {
             Write-Output ""
             Write-Output "Press enter to remove the selected apps or press CTRL+C to quit..."
             Read-Host | Out-Null
-            PrintHeader "App Removal"
+            Write-CliHeader "App Removal"
         }
     }
     else {

Scripts/CLI/Show-CliDefaultModeAppRemovalOptions.ps1

@@ -1,6 +1,6 @@
 # Shows the CLI default mode app removal options. Loops until a valid option is selected.
-function ShowCLIDefaultModeAppRemovalOptions {
-    PrintHeader 'Default Mode'
+function Show-CliDefaultModeAppRemovalOptions {
+    Write-CliHeader 'Default Mode'
 
     Write-Host "Please note: The default selection of apps includes Microsoft Teams, Spotify, Sticky Notes and more. Select option 2 to verify and change what apps are removed by the script" -ForegroundColor DarkGray
     Write-Host ""

Scripts/CLI/Show-CliDefaultModeOptions.ps1

@@ -1,5 +1,5 @@
 # Show CLI default mode options for removing apps, or set selection if RunDefaults or RunDefaultsLite parameter was passed
-function ShowCLIDefaultModeOptions {
+function Show-CliDefaultModeOptions {
     if ($RunDefaults) {
         $RemoveAppsInput = '1'
     }
@@ -7,7 +7,7 @@ function ShowCLIDefaultModeOptions {
         $RemoveAppsInput = '0'                
     }
     else {
-        $RemoveAppsInput = ShowCLIDefaultModeAppRemovalOptions
+        $RemoveAppsInput = Show-CliDefaultModeAppRemovalOptions
 
         if ($RemoveAppsInput -eq '2' -and ($script:SelectedApps.contains('Microsoft.XboxGameOverlay') -or $script:SelectedApps.contains('Microsoft.XboxGamingOverlay')) -and 
           $( Read-Host -Prompt "Disable Game Bar integration and game/screen recording? This also stops ms-gamingoverlay and ms-gamebar popups (y/n)" ) -eq 'y') {
@@ -15,40 +15,40 @@ function ShowCLIDefaultModeOptions {
         }
     }
 
-    PrintHeader 'Default Mode'
+    Write-CliHeader 'Default Mode'
 
     try {
         # Select app removal options based on user input
         switch ($RemoveAppsInput) {
             '1' {
-                AddParameter 'RemoveApps'
-                AddParameter 'Apps' 'Default'
+                Add-Parameter 'RemoveApps'
+                Add-Parameter 'Apps' 'Default'
             }
             '2' {
-                AddParameter 'RemoveApps'
-                AddParameter 'Apps' ($script:SelectedApps -join ',')
+                Add-Parameter 'RemoveApps'
+                Add-Parameter 'Apps' ($script:SelectedApps -join ',')
 
                 if ($DisableGameBarIntegrationInput) {
-                    AddParameter 'DisableDVR'
-                    AddParameter 'DisableGameBarIntegration'
+                    Add-Parameter 'DisableDVR'
+                    Add-Parameter 'DisableGameBarIntegration'
                 }
             }
         }
 
-        LoadSettings -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
+        Import-Settings -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
     }
     catch {
         Write-Error "Failed to load settings from DefaultSettings.json file: $_"
-        AwaitKeyToExit
+        Wait-ForKeyPress
     }
 
-    SaveSettings
+    Save-Settings
 
     if ($Silent) {
         # Skip change summary and confirmation prompt
         return
     }
 
-    PrintPendingChanges
-    PrintHeader 'Default Mode'
+    Write-PendingChanges
+    Write-CliHeader 'Default Mode'
 }

Scripts/CLI/Show-CliLastUsedSettings.ps1

@@ -1,13 +1,13 @@
 # Shows the CLI last used settings from LastUsedSettings.json file, displays pending changes and prompts the user to apply them.
-function ShowCLILastUsedSettings {
-    PrintHeader 'Custom Mode'
+function Show-CliLastUsedSettings {
+    Write-CliHeader 'Custom Mode'
 
     try {
-        LoadSettings -filePath $script:SavedSettingsFilePath -expectedVersion "1.0"
+        Import-Settings -filePath $script:SavedSettingsFilePath -expectedVersion "1.0"
     }
     catch {
         Write-Error "Failed to load settings from LastUsedSettings.json file: $_"
-        AwaitKeyToExit
+        Wait-ForKeyPress
     }
 
     if ($Silent) {
@@ -15,6 +15,6 @@ function ShowCLILastUsedSettings {
         return
     }
 
-    PrintPendingChanges
-    PrintHeader 'Custom Mode'
+    Write-PendingChanges
+    Write-CliHeader 'Custom Mode'
 }

Scripts/CLI/Show-CliMenuOptions.ps1

@@ -1,9 +1,9 @@
 # Shows the CLI menu options and prompts the user to select one. Loops until a valid option is selected.
-function ShowCLIMenuOptions {
+function Show-CliMenuOptions {
     Do { 
         $ModeSelectionMessage = "Please select an option (1/2)" 
 
-        PrintHeader 'Menu'
+        Write-CliHeader 'Menu'
 
         Write-Host "(1) Default mode: Quickly apply the recommended changes"
         Write-Host "(2) App removal mode: Select & remove apps, without making other changes"

Scripts/CLI/Wait-ForKeyPress.ps1

@@ -1,4 +1,4 @@
-function AwaitKeyToExit {
+function Wait-ForKeyPress {
     # Suppress prompt if Silent parameter was passed
     if (-not $Silent) {
         Write-Output ""
@@ -8,4 +8,4 @@ function AwaitKeyToExit {
 
     Stop-Transcript
     Exit
-}
+}

Scripts/CLI/Write-CliHeader.ps1

@@ -1,5 +1,5 @@
 # Prints the header for the script
-function PrintHeader {
+function Write-CliHeader {
     param (
         $title
     )
@@ -10,11 +10,11 @@ function PrintHeader {
         $fullTitle = "$fullTitle (Sysprep mode)"
     }
     else {
-        $fullTitle = "$fullTitle (User: $(GetUserName))"
+        $fullTitle = "$fullTitle (User: $(Get-UserName))"
     }
 
     Clear-Host
     Write-Host "-------------------------------------------------------------------------------------------"
     Write-Host $fullTitle
     Write-Host "-------------------------------------------------------------------------------------------"
-}
+}

Scripts/CLI/Write-PendingChanges.ps1

@@ -12,7 +12,7 @@
         After printing the summary the function pauses until the user presses
         Enter, giving them an opportunity to review and cancel via Ctrl+C.
 #>
-function PrintPendingChanges {
+function Write-PendingChanges {
     Write-Output "Win11Debloat will make the following changes:"
 
     if ($script:Params['CreateRestorePoint']) {
@@ -32,7 +32,7 @@ function PrintPendingChanges {
                 continue
             }
             'RemoveApps' {
-                $appsList = GenerateAppsList
+                $appsList = Generate-AppsList
 
                 if ($appsList.Count -eq 0) {
                     Write-Host "No valid apps were selected for removal" -ForegroundColor Yellow
@@ -56,4 +56,4 @@ function PrintPendingChanges {
     Write-Output ""
     Write-Output "Press enter to execute the script or press CTRL+C to quit..."
     Read-Host | Out-Null
-}
+}

Scripts/Features/Backup-RegistrySnapshotCapture.ps1

@@ -195,10 +195,18 @@ function Get-RegistryKeySnapshot {
     }
 }
 
+<#
+    .SYNOPSIS
+        Converts an open registry key into a backup snapshot.
+
+    .DESCRIPTION
+        Captures all values or selected value names, records missing selected values,
+        and recursively captures subkeys when requested.
+#>
 function Convert-RegistryKeyToSnapshot {
     param(
         [Parameter(Mandatory)]
-        [Microsoft.Win32.RegistryKey]$RegistryKey,
+        $RegistryKey,
         [Parameter(Mandatory)]
         [string]$FullPath,
         [bool]$CaptureAllValues = $false,
@@ -253,20 +261,34 @@ function Convert-RegistryKeyToSnapshot {
     }
 }
 
+<#
+    .SYNOPSIS
+        Converts a registry value into a serializable backup snapshot.
+
+    .DESCRIPTION
+        Preserves the value kind and normalizes supported data types for JSON
+        serialization without expanding environment-string values. REG_NONE values
+        are rejected.
+#>
 function Convert-RegistryValueToSnapshot {
     param(
         [Parameter(Mandatory)]
-        [Microsoft.Win32.RegistryKey]$RegistryKey,
+        $RegistryKey,
         [Parameter(Mandatory)]
         [AllowEmptyString()]
         [string]$ValueName
     )
 
     $valueKind = $RegistryKey.GetValueKind($ValueName)
+    if ($valueKind -eq [Microsoft.Win32.RegistryValueKind]::None) {
+        throw "REG_NONE registry values are not supported for backup. Key='$($RegistryKey.Name)' Name='$ValueName'"
+    }
+
     $value = $RegistryKey.GetValue($ValueName, $null, [Microsoft.Win32.RegistryValueOptions]::DoNotExpandEnvironmentNames)
     try {
         $normalizedValue = switch ($valueKind) {
-            ([Microsoft.Win32.RegistryValueKind]::Binary) { @($value | ForEach-Object { [int]$_ }) }
+            # Prevent an empty byte sequence from being unrolled to $null by the switch pipeline.
+            ([Microsoft.Win32.RegistryValueKind]::Binary) { if ($null -eq $value) { ,@() } else { ,@($value | ForEach-Object { [int]$_ }) } }
             ([Microsoft.Win32.RegistryValueKind]::MultiString) { @($value) }
             ([Microsoft.Win32.RegistryValueKind]::DWord) { [BitConverter]::ToUInt32([BitConverter]::GetBytes([int32]$value), 0) }
             ([Microsoft.Win32.RegistryValueKind]::QWord) { [BitConverter]::ToUInt64([BitConverter]::GetBytes([int64]$value), 0) }
@@ -287,12 +309,20 @@ function Convert-RegistryValueToSnapshot {
     }
 }
 
+<#
+    .SYNOPSIS
+        Describes the user profile targeted by a registry backup.
+
+    .DESCRIPTION
+        Returns DefaultUserProfile for Sysprep, User:<name> for an explicit user,
+        or CurrentUser:<name> otherwise.
+#>
 function Get-RegistryBackupTargetDescription {
     if ($script:Params.ContainsKey('Sysprep')) {
         return 'DefaultUserProfile'
     }
 
-    $resolvedUserName = [string](GetUserName)
+    $resolvedUserName = [string](Get-UserName)
 
     if ($script:Params.ContainsKey('User')) {
         return "User:$resolvedUserName"

Scripts/Features/Backup-RegistryState.ps1

@@ -37,7 +37,7 @@ function New-RegistrySettingsBackup {
     $backupFilePath = Join-Path $backupDirectory $backupFileName
 
     $backupConfig = Get-RegistryBackupPayload -SelectedFeatures $selectedFeatures -UndoFeatures $undoFeatures -CreatedAt $timestamp
-    if (-not (SaveToFile -Config $backupConfig -FilePath $backupFilePath -MaxDepth 25)) {
+    if (-not (Save-ToFile -Config $backupConfig -FilePath $backupFilePath -MaxDepth 25)) {
         throw "Failed to save registry backup to '$backupFilePath'"
     }
 

Scripts/Features/Ensure-SystemRestorePoint.ps1

@@ -1,4 +1,4 @@
-function CreateSystemRestorePoint {
+function Invoke-SystemRestorePoint {
     $SysRestore = Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore" -Name "RPSessionInterval"
     $failed = $false
 

Scripts/Features/Get-CurrentTweakState.ps1

@@ -66,7 +66,7 @@ function Test-FeatureApplied {
                 return (Test-StoreSearchSuggestionsDisabledForAllUsers)
             }
 
-            $storeDbPath = GetStoreAppsDatabasePathForUser -UserName (GetUserName)
+            $storeDbPath = Get-StoreAppsDatabasePathForUser -UserName (Get-UserName)
 
             return (Test-StoreSearchSuggestionsDisabled -StoreAppsDatabase $storeDbPath)
         }

Scripts/Features/Import-RegistryFile.ps1

@@ -1,5 +1,5 @@
 # Import & execute regfile
-function ImportRegistryFile {
+function Import-RegistryFile {
     param (
         $message,
         $path

Scripts/Features/Invoke-Changes.ps1

@@ -4,7 +4,7 @@
 
     .DESCRIPTION
         Handles two categories of features:
-        - Registry-backed: imports the .reg file via ImportRegistryFile, then runs
+        - Registry-backed: imports the .reg file via Import-RegistryFile, then runs
         any post-import side effects (e.g., removing companion app packages).
         - Custom logic: app removal, Windows optional features, start menu
         replacement, and other special-case features.
@@ -21,17 +21,17 @@ function Invoke-FeatureApply {
 
     # ---- Registry-backed features: import .reg file, then handle side effects ----
     if ($feature.RegistryKey) {
-        ImportRegistryFile "> $applyText..." $feature.RegistryKey
+        Import-RegistryFile "> $applyText..." $feature.RegistryKey
 
         # Post-import side effects for specific features
         switch ($FeatureId) {
             'DisableBing' {
                 # Also remove the app package for Bing search
-                RemoveApps @('Microsoft.BingSearch')
+                Remove-SelectedApps @('Microsoft.BingSearch')
             }
             'DisableCopilot' {
                 # Also remove the app packages for Copilot
-                RemoveApps @('Microsoft.Copilot', 'XP9CXNGPPJ97XX')
+                Remove-SelectedApps @('Microsoft.Copilot', 'XP9CXNGPPJ97XX')
             }
             'DisableTelemetry' {
                 # Also disable telemetry scheduled tasks
@@ -44,8 +44,8 @@ function Invoke-FeatureApply {
     # ---- Custom features (no registry backing, or special handling required) ----
     switch ($FeatureId) {
         'RemoveApps' {
-            Write-Host "> $applyText for $(GetFriendlyTargetUserName)..."
-            $appsList = GenerateAppsList
+            Write-Host "> $applyText for $(Get-FriendlyTargetUserName)..."
+            $appsList = Generate-AppsList
 
             if ($appsList.Count -eq 0) {
                 Write-Host "No valid apps were selected for removal" -ForegroundColor Yellow
@@ -54,19 +54,19 @@ function Invoke-FeatureApply {
             }
 
             Write-Host "$($appsList.Count) apps selected for removal"
-            RemoveApps $appsList
+            Remove-SelectedApps $appsList
             return
         }
         'RemoveGamingApps' {
             $appsList = @('Microsoft.GamingApp', 'Microsoft.XboxGameOverlay', 'Microsoft.XboxGamingOverlay')
             Write-Host "> $applyText..."
-            RemoveApps $appsList
+            Remove-SelectedApps $appsList
             return
         }
         'RemoveHPApps' {
             $appsList = @('AD2F1837.HPAIExperienceCenter', 'AD2F1837.HPJumpStarts', 'AD2F1837.HPPCHardwareDiagnosticsWindows', 'AD2F1837.HPPowerManager', 'AD2F1837.HPPrivacySettings', 'AD2F1837.HPSupportAssistant', 'AD2F1837.HPSureShieldAI', 'AD2F1837.HPSystemInformation', 'AD2F1837.HPQuickDrop', 'AD2F1837.HPWorkWell', 'AD2F1837.myHP', 'AD2F1837.HPDesktopSupportUtilities', 'AD2F1837.HPQuickTouch', 'AD2F1837.HPEasyClean', 'AD2F1837.HPConnectedMusic', 'AD2F1837.HPFileViewer', 'AD2F1837.HPRegistration', 'AD2F1837.HPWelcome', 'AD2F1837.HPConnectedPhotopoweredbySnapfish', 'AD2F1837.HPPrinterControl')
             Write-Host "> $applyText..."
-            RemoveApps $appsList
+            Remove-SelectedApps $appsList
             return
         }
         'DisableWidgets' {
@@ -76,46 +76,46 @@ function Invoke-FeatureApply {
                 Get-Process *Widget* -ErrorAction SilentlyContinue | Stop-Process
             }
 
-            RemoveApps @('Microsoft.StartExperiencesApp','MicrosoftWindows.Client.WebExperience','Microsoft.WidgetsPlatformRuntime')
+            Remove-SelectedApps @('Microsoft.StartExperiencesApp','MicrosoftWindows.Client.WebExperience','Microsoft.WidgetsPlatformRuntime')
             return
         }
         'EnableWindowsSandbox' {
             Write-Host "> $applyText..."
-            EnableWindowsFeature "Containers-DisposableClientVM"
+            Enable-WindowsFeature "Containers-DisposableClientVM"
             Write-Host ""
             return
         }
         'EnableWindowsSubsystemForLinux' {
             Write-Host "> $applyText..."
-            EnableWindowsFeature "VirtualMachinePlatform"
-            EnableWindowsFeature "Microsoft-Windows-Subsystem-Linux"
+            Enable-WindowsFeature "VirtualMachinePlatform"
+            Enable-WindowsFeature "Microsoft-Windows-Subsystem-Linux"
             Write-Host ""
             return
         }
         'ClearStart' {
-            Write-Host "> $applyText for user $(GetUserName)..."
-            $startMenuBinFile = GetStartMenuBinPathForUser -UserName (GetUserName)
+            Write-Host "> $applyText for user $(Get-UserName)..."
+            $startMenuBinFile = Get-StartMenuBinPathForUser -UserName (Get-UserName)
             if (-not [string]::IsNullOrWhiteSpace($startMenuBinFile)) {
-                ReplaceStartMenu -startMenuBinFile $startMenuBinFile
+                Replace-StartMenu -startMenuBinFile $startMenuBinFile
             }
             Write-Host ""
             return
         }
         'ReplaceStart' {
-            Write-Host "> $applyText for user $(GetUserName)..."
-            $startMenuBinFile = GetStartMenuBinPathForUser -UserName (GetUserName)
+            Write-Host "> $applyText for user $(Get-UserName)..."
+            $startMenuBinFile = Get-StartMenuBinPathForUser -UserName (Get-UserName)
             if (-not [string]::IsNullOrWhiteSpace($startMenuBinFile)) {
-                ReplaceStartMenu -startMenuBinFile $startMenuBinFile -startMenuTemplate $script:Params.Item("ReplaceStart")
+                Replace-StartMenu -startMenuBinFile $startMenuBinFile -startMenuTemplate $script:Params.Item("ReplaceStart")
             }
             Write-Host ""
             return
         }
         'ClearStartAllUsers' {
-            ReplaceStartMenuForAllUsers
+            Replace-StartMenuForAllUsers
             return
         }
         'ReplaceStartAllUsers' {
-            ReplaceStartMenuForAllUsers -startMenuTemplate $script:Params.Item("ReplaceStartAllUsers")
+            Replace-StartMenuForAllUsers -startMenuTemplate $script:Params.Item("ReplaceStartAllUsers")
             return
         }
         'DisableStoreSearchSuggestions' {
@@ -126,10 +126,10 @@ function Invoke-FeatureApply {
                 return
             }
 
-            Write-Host "> Disabling Microsoft Store search suggestions for user $(GetUserName)..."
-            $storeDb = GetStoreAppsDatabasePathForUser -UserName (GetUserName)
+            Write-Host "> Disabling Microsoft Store search suggestions for user $(Get-UserName)..."
+            $storeDb = Get-StoreAppsDatabasePathForUser -UserName (Get-UserName)
             if ($storeDb) {
-                DisableStoreSearchSuggestions -StoreAppsDatabase $storeDb
+                Set-StoreSearchSuggestionsDisabled -StoreAppsDatabase $storeDb
             }
             Write-Host ""
             return
@@ -145,7 +145,7 @@ function Invoke-FeatureApply {
     .DESCRIPTION
         Handles undo for features that require custom logic rather than a simple
         .reg file import. Features with a RegistryUndoKey are handled directly
-        via ImportRegistryFile in Invoke-UndoFeatures.
+        via Import-RegistryFile in Invoke-UndoFeatures.
 #>
 function Invoke-FeatureUndo {
     param(
@@ -164,24 +164,24 @@ function Invoke-FeatureUndo {
                 return
             }
 
-            Write-Host "> Re-enabling Microsoft Store search suggestions for user $(GetUserName)..."
-            $storeDb = GetStoreAppsDatabasePathForUser -UserName (GetUserName)
+            Write-Host "> Re-enabling Microsoft Store search suggestions for user $(Get-UserName)..."
+            $storeDb = Get-StoreAppsDatabasePathForUser -UserName (Get-UserName)
             if ($storeDb) {
-                EnableStoreSearchSuggestions -StoreAppsDatabase $storeDb
+                Set-StoreSearchSuggestionsEnabled -StoreAppsDatabase $storeDb
             }
             Write-Host ""
             return
         }
         'EnableWindowsSandbox' {
             Write-Host "> $($feature.ApplyUndoText)..."
-            DisableWindowsFeature 'Containers-DisposableClientVM'
+            Disable-WindowsFeature 'Containers-DisposableClientVM'
             Write-Host ""
             return
         }
         'EnableWindowsSubsystemForLinux' {
             Write-Host "> $($feature.ApplyUndoText)..."
-            DisableWindowsFeature 'Microsoft-Windows-Subsystem-Linux'
-            DisableWindowsFeature 'VirtualMachinePlatform'
+            Disable-WindowsFeature 'Microsoft-Windows-Subsystem-Linux'
+            Disable-WindowsFeature 'VirtualMachinePlatform'
             Write-Host ""
             return
         }
@@ -287,7 +287,7 @@ function Invoke-UndoFeatures {
         }
 
         if ($f -and $f.RegistryUndoKey) {
-            ImportRegistryFile "> $undoText" (Resolve-UndoRegFilePath $f.RegistryUndoKey)
+            Import-RegistryFile "> $undoText" (Resolve-UndoRegFilePath $f.RegistryUndoKey)
         }
 
         Invoke-FeatureUndo -FeatureId $featureId
@@ -311,8 +311,10 @@ function Invoke-UndoFeatures {
         (used by the GUI modal). Cancellation is checked between each step.
 #>
 function Invoke-AllChanges {
+    if ($script:CancelRequested) { return }
+
     # Guard: prevent running as SYSTEM account without explicit target user
-    $isSystem = ([Security.Principal.WindowsIdentity]::GetCurrent().User.Value -eq 'S-1-5-18')
+    $isSystem = Test-RunningAsSystem
     if ($isSystem -and -not $script:Params.ContainsKey("User") -and -not $script:Params.ContainsKey("Sysprep")) {
         throw "Win11Debloat is running as the SYSTEM account. Use the '-User' or '-Sysprep' parameter to target a specific user."
     }
@@ -355,6 +357,7 @@ function Invoke-AllChanges {
     # Phase 1: Registry backup
     # ================================================================
     if ($needsBackup) {
+        if ($script:CancelRequested) { return }
         $step++
         if ($script:ApplyProgressCallback) {
             & $script:ApplyProgressCallback $step $totalSteps "Creating registry backup..."
@@ -384,6 +387,7 @@ function Invoke-AllChanges {
     # Phase 2: System restore point
     # ================================================================
     if ($script:Params.ContainsKey("CreateRestorePoint")) {
+        if ($script:CancelRequested) { return }
         $step++
         if ($script:ApplyProgressCallback) {
             & $script:ApplyProgressCallback $step $totalSteps "Creating system restore point, this may take a moment..."
@@ -394,7 +398,7 @@ function Invoke-AllChanges {
         }
         else {
             Write-Host "> Creating a system restore point..."
-            CreateSystemRestorePoint
+            Invoke-SystemRestorePoint
             Write-Host ""
         }
     }
@@ -407,6 +411,8 @@ function Invoke-AllChanges {
         $step += $applyIds.Count
     }
 
+    if ($script:CancelRequested) { return }
+
     # ================================================================
     # Phase 4: Undo features
     # ================================================================
@@ -423,3 +429,19 @@ function Invoke-AllChanges {
         Write-Host "$($script:RegistryImportFailures) registry import change(s) failed. See output above for details." -ForegroundColor Yellow
     }
 }
+
+<#
+    .SYNOPSIS
+        Tests whether Win11Debloat is running under the SYSTEM account.
+
+    .DESCRIPTION
+        Compares the current Windows identity's security identifier (SID) with
+        the well-known Local System SID (S-1-5-18).
+
+    .OUTPUTS
+        System.Boolean
+        Returns $true when the current process runs as SYSTEM; otherwise, $false.
+#>
+function Test-RunningAsSystem {
+    return ([Security.Principal.WindowsIdentity]::GetCurrent().User.Value -eq 'S-1-5-18')
+}

Scripts/Features/Invoke-RestartExplorer.ps1

@@ -5,7 +5,7 @@
     .DESCRIPTION
     Restarts the Explorer process to ensure all UI modifications take effect. Shows a warning if any of the applied features require a reboot to take full effect.
 #>
-function RestartExplorer {
+function Invoke-RestartExplorer {
     if ($script:Params.ContainsKey("WhatIf")) {
         Write-Host "[WhatIf] Restart the Windows Explorer process" -ForegroundColor Cyan
         return
@@ -32,4 +32,4 @@ function RestartExplorer {
     else {
         Write-Host "Unable to restart Windows Explorer process, please manually reboot your PC to apply all changes" -ForegroundColor Yellow
     }
-}
+}

Scripts/Features/Registry-BackupValidation.ps1

@@ -248,6 +248,14 @@ function New-RegistryBackupAllowListPlanMap {
     return $planMap
 }
 
+<#
+    .SYNOPSIS
+        Converts registry value names into a case-insensitive set.
+
+    .DESCRIPTION
+        Preserves empty names and prevents PowerShell from enumerating the returned
+        HashSet.
+#>
 function ConvertTo-RegistryValueNameSet {
     param(
         [AllowEmptyCollection()]
@@ -259,9 +267,18 @@ function ConvertTo-RegistryValueNameSet {
         $null = $valueNameSet.Add([string]$valueName)
     }
 
-    return $valueNameSet
+    # Prevent PowerShell from enumerating the HashSet into an array or single string
+    return ,$valueNameSet
 }
 
+<#
+    .SYNOPSIS
+        Validates a registry snapshot against the selected-feature allow list.
+
+    .DESCRIPTION
+        Recursively validates snapshot paths, value names, value kinds, and value
+        data, appending validation errors to the supplied list.
+#>
 function Test-RegistrySnapshotAgainstAllowList {
     param(
         [Parameter(Mandatory)]
@@ -301,7 +318,7 @@ function Test-RegistrySnapshotAgainstAllowList {
                 $Errors.Add("Backup contains unsupported registry value kind '$kindName' for '$valueReference'.")
             }
             elseif (-not (Test-RegistryValueDataMatchesKind -KindName $kindName -Data $valueSnapshot.Data)) {
-                $Errors.Add("Backup value '$valueReference' has Data that does not fit its Kind '$kindName'.")
+                $Errors.Add("Backup contains invalid registry data for kind '$kindName' at '$valueReference'.")
             }
         }
         elseif (-not [string]::IsNullOrWhiteSpace($kindName)) {
@@ -314,6 +331,64 @@ function Test-RegistrySnapshotAgainstAllowList {
     }
 }
 
+<#
+    .SYNOPSIS
+        Tests whether backed-up registry data is valid for its declared value kind.
+
+    .DESCRIPTION
+        Rejects corrupted or hand-edited backup data that cannot be restored safely,
+        such as a DWord that overflows UInt32 or binary data containing an invalid byte.
+        This validation runs before Restore-RegistryKeySnapshot mutates the live
+        registry, preventing a failed conversion from leaving a partially restored key.
+
+    .PARAMETER KindName
+        The declared registry value kind name, such as DWord, QWord, or Binary.
+
+    .PARAMETER Data
+        The backed-up value data to validate against the declared kind.
+
+    .OUTPUTS
+        System.Boolean
+#>
+function Test-RegistryValueDataMatchesKind {
+    param(
+        [Parameter(Mandatory)]
+        [string]$KindName,
+        [AllowNull()]
+        $Data
+    )
+
+    $kind = [System.Enum]::Parse([Microsoft.Win32.RegistryValueKind], $KindName, $true)
+    switch ($kind) {
+        ([Microsoft.Win32.RegistryValueKind]::DWord) {
+            $parsed = [uint32]0
+            return [uint32]::TryParse([string]$Data, [System.Globalization.NumberStyles]::Integer, [System.Globalization.CultureInfo]::InvariantCulture, [ref]$parsed)
+        }
+        ([Microsoft.Win32.RegistryValueKind]::QWord) {
+            $parsed = [uint64]0
+            return [uint64]::TryParse([string]$Data, [System.Globalization.NumberStyles]::Integer, [System.Globalization.CultureInfo]::InvariantCulture, [ref]$parsed)
+        }
+        ([Microsoft.Win32.RegistryValueKind]::Binary) {
+            if ($null -eq $Data -or $Data -isnot [array]) { return $false }
+            foreach ($item in @($Data)) {
+                if ($item -isnot [ValueType] -and $item -isnot [string]) { return $false }
+                $parsed = 0
+                if (-not [int]::TryParse([string]$item, [ref]$parsed) -or $parsed -lt 0 -or $parsed -gt 255) {
+                    return $false
+                }
+            }
+            return $true
+        }
+        ([Microsoft.Win32.RegistryValueKind]::MultiString) {
+            foreach ($item in @($Data)) {
+                if ($item -isnot [string]) { return $false }
+            }
+            return $true
+        }
+        default { return ($null -eq $Data -or $Data -is [string]) }
+    }
+}
+
 function Test-RegistryValueAllowedByPlan {
     param(
         [Parameter(Mandatory)]
@@ -431,6 +506,14 @@ function Get-NormalizedRegistryPathKey {
     return "$normalizedHive\\$normalizedSubKey"
 }
 
+<#
+    .SYNOPSIS
+        Tests whether a registry value-kind name is supported in backups.
+
+    .DESCRIPTION
+        Parses kind names case-insensitively and rejects empty, invalid, Unknown,
+        and None values.
+#>
 function Test-RegistryValueKindNameSupported {
     param(
         [string]$KindName
@@ -442,64 +525,10 @@ function Test-RegistryValueKindNameSupported {
 
     try {
         $kind = [System.Enum]::Parse([Microsoft.Win32.RegistryValueKind], $KindName, $true)
-        return $kind -ne [Microsoft.Win32.RegistryValueKind]::Unknown
+        return $kind -notin @([Microsoft.Win32.RegistryValueKind]::Unknown, [Microsoft.Win32.RegistryValueKind]::None)
     }
     catch {
         return $false
     }
 }
 
-<#
-    .SYNOPSIS
-        Checks whether a backed-up value's Data can be converted to its declared Kind.
-
-    .DESCRIPTION
-        A corrupted or hand-edited backup can have Data that doesn't fit its declared
-        Kind (e.g. Kind=DWord with Data=4294967296, which overflows uint32). Restore-
-        RegistryValueSnapshot's Convert-RegistryValueDataFromBackup performs the same
-        narrowing casts without a try/catch, and by the time it runs the live registry
-        subtree has already been deleted (Restore-RegistryKeySnapshot deletes before
-        rewriting) - so an invalid Data/Kind pairing must be rejected here, before any
-        restore begins, not left to fail mid-restore. See #686.
-
-    .PARAMETER KindName
-        The value's declared registry kind name (e.g. "DWord", "QWord", "String").
-
-    .PARAMETER Data
-        The value's backed-up data to validate against KindName.
-#>
-function Test-RegistryValueDataMatchesKind {
-    param(
-        [string]$KindName,
-        $Data
-    )
-
-    $kind = [System.Enum]::Parse([Microsoft.Win32.RegistryValueKind], $KindName, $true)
-
-    switch ($kind) {
-        ([Microsoft.Win32.RegistryValueKind]::DWord) {
-            try {
-                [void][uint32]$Data
-                return $true
-            }
-            catch {
-                return $false
-            }
-        }
-        ([Microsoft.Win32.RegistryValueKind]::QWord) {
-            try {
-                [void][uint64]$Data
-                return $true
-            }
-            catch {
-                return $false
-            }
-        }
-        default {
-            # String/MultiString/Binary/None conversions in Convert-RegistryValueDataFromBackup
-            # cannot throw for arbitrary Data - they stringify, array-map to strings, or fall
-            # back to an empty byte array / null.
-            return $true
-        }
-    }
-}

Scripts/Features/Replace-StartMenu.ps1

@@ -14,12 +14,12 @@
     bundled with the script (Assets/Start/start2.bin).
 
     .EXAMPLE
-    ReplaceStartMenuForAllUsers
+    Replace-StartMenuForAllUsers
 
     .EXAMPLE
-    ReplaceStartMenuForAllUsers -startMenuTemplate "C:\CustomLayout.bin"
+    Replace-StartMenuForAllUsers -startMenuTemplate "C:\CustomLayout.bin"
 #>
-function ReplaceStartMenuForAllUsers {
+function Replace-StartMenuForAllUsers {
     param (
         [string]$startMenuTemplate = "$script:AssetsPath\Start\start2.bin"
     )
@@ -34,16 +34,16 @@ function ReplaceStartMenuForAllUsers {
     }
 
     # Get path to start menu file for all users
-    $userPathString = GetUserDirectory -userName "*" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState"
+    $userPathString = Get-UserDirectory -userName "*" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState"
     $usersStartMenuPaths = Get-ChildItem -Path $userPathString -ErrorAction SilentlyContinue
 
     # Go through all users and replace the start menu file
     ForEach ($startMenuPath in $usersStartMenuPaths) {
-        ReplaceStartMenu -startMenuBinFile "$($startMenuPath.Fullname)\start2.bin" -startMenuTemplate $startMenuTemplate
+        Replace-StartMenu -startMenuBinFile "$($startMenuPath.Fullname)\start2.bin" -startMenuTemplate $startMenuTemplate
     }
 
     # Also replace the start menu file for the default user profile
-    $defaultStartMenuPath = GetUserDirectory -userName "Default" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState" -exitIfPathNotFound $false
+    $defaultStartMenuPath = Get-UserDirectory -userName "Default" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState" -exitIfPathNotFound $false
 
     if ($script:Params.ContainsKey("WhatIf")) {
         Write-Host "[WhatIf] Replace Start Menu for Default user profile with template $startMenuTemplate" -ForegroundColor Cyan
@@ -57,7 +57,7 @@ function ReplaceStartMenuForAllUsers {
     }
 
     # Copy template to default profile
-    ReplaceStartMenu -startMenuBinFile "$($defaultStartMenuPath)\start2.bin" -startMenuTemplate $startMenuTemplate
+    Replace-StartMenu -startMenuBinFile "$($defaultStartMenuPath)\start2.bin" -startMenuTemplate $startMenuTemplate
     Write-Host "Replaced start menu for the default user profile"
     Write-Host ""
 }
@@ -83,12 +83,12 @@ function ReplaceStartMenuForAllUsers {
     bundled with the script (Assets/Start/start2.bin).
 
     .EXAMPLE
-    ReplaceStartMenu -startMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
+    Replace-StartMenu -startMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
 
     .EXAMPLE
-    ReplaceStartMenu -startMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin" -startMenuTemplate "C:\CustomLayout.bin"
+    Replace-StartMenu -startMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin" -startMenuTemplate "C:\CustomLayout.bin"
 #>
-function ReplaceStartMenu {
+function Replace-StartMenu {
     param (
         [Parameter(Mandatory)]
         [string]$startMenuBinFile,
@@ -106,7 +106,7 @@ function ReplaceStartMenu {
         return
     }
 
-    $userName = GetStartMenuUserNameFromPath -StartMenuBinFile $startMenuBinFile
+    $userName = Get-StartMenuUserNameFromPath -StartMenuBinFile $startMenuBinFile
 
     if ($script:Params.ContainsKey("WhatIf")) {
         Write-Host "[WhatIf] Replace Start Menu for user $userName with template $startMenuTemplate" -ForegroundColor Cyan
@@ -147,12 +147,12 @@ function ReplaceStartMenu {
     The target username. Pass an empty string or omit to resolve for the current user.
 
     .EXAMPLE
-    GetStartMenuBinPathForUser -UserName "Jeff"
+    Get-StartMenuBinPathForUser -UserName "Jeff"
 
     .EXAMPLE
-    GetStartMenuBinPathForUser -UserName "Default"
+    Get-StartMenuBinPathForUser -UserName "Default"
 #>
-function GetStartMenuBinPathForUser {
+function Get-StartMenuBinPathForUser {
     param(
         [string]$UserName
     )
@@ -161,7 +161,7 @@ function GetStartMenuBinPathForUser {
         return "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
     }
 
-    return (GetUserDirectory -userName $UserName -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin" -exitIfPathNotFound $false)
+    return (Get-UserDirectory -userName $UserName -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin" -exitIfPathNotFound $false)
 }
 
 <#
@@ -177,9 +177,9 @@ function GetStartMenuBinPathForUser {
     The full path to a start2.bin file.
 
     .EXAMPLE
-    GetStartMenuUserNameFromPath -StartMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
+    Get-StartMenuUserNameFromPath -StartMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
 #>
-function GetStartMenuUserNameFromPath {
+function Get-StartMenuUserNameFromPath {
     param(
         [string]$StartMenuBinFile
     )
@@ -230,7 +230,7 @@ function Get-StartMenuBackupPath {
         return $null
     }
     else {
-        $userPathString = GetUserDirectory -userName "*" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState"
+        $userPathString = Get-UserDirectory -userName "*" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState"
         $usersStartMenuPaths = Get-ChildItem -Path $userPathString -ErrorAction SilentlyContinue
         foreach ($startMenuPath in $usersStartMenuPaths) {
             $latestBackup = Get-ChildItem -Path (Join-Path $startMenuPath.FullName 'Win11Debloat-StartBackup-*.bak') -ErrorAction SilentlyContinue |
@@ -261,19 +261,19 @@ function Get-StartMenuBackupPath {
     finds the latest Win11Debloat-StartBackup-*.bak file.
 
     .EXAMPLE
-    RestoreStartMenuFromBackup -StartMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
+    Restore-StartMenuFromBackup -StartMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin"
 
     .EXAMPLE
-    RestoreStartMenuFromBackup -StartMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin" -BackupFilePath "C:\Backups\Win11Debloat-StartBackup-20260101_120000.bak"
+    Restore-StartMenuFromBackup -StartMenuBinFile "$env:LOCALAPPDATA\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState\start2.bin" -BackupFilePath "C:\Backups\Win11Debloat-StartBackup-20260101_120000.bak"
 #>
-function RestoreStartMenuFromBackup {
+function Restore-StartMenuFromBackup {
     param(
         [Parameter(Mandatory)]
         [string]$StartMenuBinFile,
         [string]$BackupFilePath
     )
 
-    $userName = GetStartMenuUserNameFromPath -StartMenuBinFile $StartMenuBinFile
+    $userName = Get-StartMenuUserNameFromPath -StartMenuBinFile $StartMenuBinFile
     $backupBinFile = if ([string]::IsNullOrWhiteSpace($BackupFilePath)) {
         # Auto-detect latest backup in the same folder as the start2.bin
         $startMenuDir = Split-Path $StartMenuBinFile -Parent
@@ -342,19 +342,19 @@ function RestoreStartMenuFromBackup {
 
     .DESCRIPTION
     Resolves the start2.bin path for the currently logged-in user, then
-    delegates to RestoreStartMenuFromBackup.
+    delegates to Restore-StartMenuFromBackup.
 
     .PARAMETER BackupFilePath
     Path to the backup file to restore from. If omitted, automatically
     finds the latest Win11Debloat-StartBackup-*.bak file.
 
     .EXAMPLE
-    RestoreStartMenu
+    Restore-StartMenu
 
     .EXAMPLE
-    RestoreStartMenu -BackupFilePath "C:\Backups\Win11Debloat-StartBackup-20260101_120000.bak"
+    Restore-StartMenu -BackupFilePath "C:\Backups\Win11Debloat-StartBackup-20260101_120000.bak"
 #>
-function RestoreStartMenu {
+function Restore-StartMenu {
     param(
         [string]$BackupFilePath
     )
@@ -364,7 +364,7 @@ function RestoreStartMenu {
 
     Write-Host "Restoring start menu for user $targetUserName from backup..."
 
-    return RestoreStartMenuFromBackup -StartMenuBinFile $startMenuBinFile -BackupFilePath $BackupFilePath
+    return Restore-StartMenuFromBackup -StartMenuBinFile $startMenuBinFile -BackupFilePath $BackupFilePath
 }
 
 <#
@@ -384,17 +384,17 @@ function RestoreStartMenu {
     LocalState folder.
 
     .EXAMPLE
-    RestoreStartMenuForAllUsers
+    Restore-StartMenuForAllUsers
 
     .EXAMPLE
-    RestoreStartMenuForAllUsers -BackupFilePath "C:\Backups\Win11Debloat-StartBackup-20260101_120000.bak"
+    Restore-StartMenuForAllUsers -BackupFilePath "C:\Backups\Win11Debloat-StartBackup-20260101_120000.bak"
 #>
-function RestoreStartMenuForAllUsers {
+function Restore-StartMenuForAllUsers {
     param(
         [string]$BackupFilePath
     )
 
-    $userPathString = GetUserDirectory -userName "*" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState"
+    $userPathString = Get-UserDirectory -userName "*" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState"
     $usersStartMenuPaths = Get-ChildItem -Path $userPathString -ErrorAction SilentlyContinue
     $results = @()
 
@@ -402,10 +402,10 @@ function RestoreStartMenuForAllUsers {
 
     foreach ($startMenuPath in $usersStartMenuPaths) {
         $startMenuBinFile = Join-Path $startMenuPath.FullName 'start2.bin'
-        $results += RestoreStartMenuFromBackup -StartMenuBinFile $startMenuBinFile -BackupFilePath $BackupFilePath
+        $results += Restore-StartMenuFromBackup -StartMenuBinFile $startMenuBinFile -BackupFilePath $BackupFilePath
     }
 
-    $defaultStartMenuPath = GetUserDirectory -userName "Default" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState" -exitIfPathNotFound $false
+    $defaultStartMenuPath = Get-UserDirectory -userName "Default" -fileName "AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\LocalState" -exitIfPathNotFound $false
 
     if (Test-Path $defaultStartMenuPath) {
         $defaultStartMenuBinFile = Join-Path $defaultStartMenuPath 'start2.bin'

Scripts/Features/Restore-RegistryApplyState.ps1

@@ -1,3 +1,16 @@
+<#
+    .SYNOPSIS
+        Runs a script block against the registry hive for a backup target.
+
+    .PARAMETER Target
+        A supported backup target: DefaultUserProfile or User:<user name>.
+
+    .PARAMETER ScriptBlock
+        The operation to run after the target user hive is available.
+
+    .PARAMETER ArgumentObject
+        Optional object passed to the script block.
+#>
 function Invoke-WithLoadedRestoreHive {
     param(
         [Parameter(Mandatory)]
@@ -24,6 +37,13 @@ function Invoke-WithLoadedRestoreHive {
     Invoke-WithTargetUserHive -TargetUserName $targetUserName -ScriptBlock $ScriptBlock -ArgumentObject $ArgumentObject
 }
 
+<#
+    .SYNOPSIS
+        Restores a registry key and its child keys from a backup snapshot.
+
+    .PARAMETER Snapshot
+        The saved registry-key state, including existence, values, and subkeys.
+#>
 function Restore-RegistryKeySnapshot {
     param(
         [Parameter(Mandatory)]
@@ -74,10 +94,20 @@ function Restore-RegistryKeySnapshot {
     }
 }
 
+<#
+    .SYNOPSIS
+        Restores or removes a registry value from a backup snapshot.
+
+    .PARAMETER RegistryKey
+        The open registry key that contains the value.
+
+    .PARAMETER Snapshot
+        The saved registry-value state to apply.
+#>
 function Restore-RegistryValueSnapshot {
     param(
         [Parameter(Mandatory)]
-        [Microsoft.Win32.RegistryKey]$RegistryKey,
+        $RegistryKey,
         [Parameter(Mandatory)]
         $Snapshot
     )
@@ -101,21 +131,20 @@ function Restore-RegistryValueSnapshot {
         $RegistryKey.SetValue($valueName, $normalizedData, $valueKind)
     }
     catch {
-        $retryBytes = Convert-BackupDataToByteArray -Data $Snapshot.Data
-        if ($null -ne $retryBytes) {
-            try {
-                $RegistryKey.SetValue($valueName, $retryBytes, [Microsoft.Win32.RegistryValueKind]::Binary)
-                return
-            }
-            catch {
-                # Fall through to original error message for context.
-            }
-        }
-
         throw "Failed setting registry value '$valueName' in '$($RegistryKey.Name)': $($_.Exception.Message)"
     }
 }
 
+<#
+    .SYNOPSIS
+        Converts a backed-up registry value-kind name to its .NET enum value.
+
+    .PARAMETER KindName
+        The registry value-kind name stored in the backup.
+
+    .OUTPUTS
+        Microsoft.Win32.RegistryValueKind
+#>
 function Convert-RegistryValueKindFromBackup {
     param(
         [string]$KindName
@@ -133,6 +162,16 @@ function Convert-RegistryValueKindFromBackup {
     }
 }
 
+<#
+    .SYNOPSIS
+        Converts backed-up data to a value suitable for registry restoration.
+
+    .PARAMETER Kind
+        The registry value kind that determines how the data is converted.
+
+    .PARAMETER Data
+        The serialized value data from the backup.
+#>
 function Convert-RegistryValueDataFromBackup {
     param(
         [Microsoft.Win32.RegistryValueKind]$Kind,
@@ -148,15 +187,20 @@ function Convert-RegistryValueDataFromBackup {
             $unsigned = [uint64]$Data
             return [BitConverter]::ToInt64([BitConverter]::GetBytes($unsigned), 0)
         }
-        ([Microsoft.Win32.RegistryValueKind]::MultiString) { return @($Data | ForEach-Object { [string]$_ }) }
+        ([Microsoft.Win32.RegistryValueKind]::MultiString) { return ,([string[]]@($Data | ForEach-Object { [string]$_ })) }
         ([Microsoft.Win32.RegistryValueKind]::Binary) {
+            if ($null -eq $Data) {
+                return ,(New-Object byte[] 0)
+            }
+
             $bytes = Convert-BackupDataToByteArray -Data $Data
             if ($null -eq $bytes) {
-                return (New-Object byte[] 0)
+                throw 'Invalid binary registry data in backup. Expected byte values from 0 through 255.'
             }
-            return $bytes
+            # Keep the byte array intact instead of writing each byte to the
+            # pipeline. RegistryKey.SetValue requires a byte[] for Binary.
+            return ,$bytes
         }
-        ([Microsoft.Win32.RegistryValueKind]::None) { return $null }
         default {
             if ($null -ne $Data) {
                 return [string]$Data
@@ -167,6 +211,17 @@ function Convert-RegistryValueDataFromBackup {
     }
 }
 
+<#
+    .SYNOPSIS
+        Converts serialized binary backup data to a byte array.
+
+    .PARAMETER Data
+        A byte array or collection of integer byte values from the backup.
+
+    .OUTPUTS
+        System.Byte[]
+        Returns $null when the input contains invalid byte data.
+#>
 function Convert-BackupDataToByteArray {
     param(
         $Data
@@ -207,18 +262,3 @@ function Convert-BackupDataToByteArray {
 
     return ,$bytes
 }
-
-function Remove-RegistrySubKeyTreeIfExists {
-    param(
-        [Parameter(Mandatory)]
-        [Microsoft.Win32.RegistryKey]$RootKey,
-        [Parameter(Mandatory)]
-        [string]$SubKeyPath
-    )
-
-    $existing = $RootKey.OpenSubKey($SubKeyPath, $false)
-    if ($existing) {
-        $existing.Close()
-        $RootKey.DeleteSubKeyTree($SubKeyPath, $false)
-    }
-}

Scripts/Features/Restore-RegistryBackup.ps1

@@ -12,9 +12,9 @@
 
     .OUTPUTS
         PSCustomObject
-        A normalized registry backup object produced by Normalize-RegistryBackup.
+        A normalized registry backup object produced by ConvertTo-NormalizedRegistryBackup.
 #>
-function Load-RegistryBackupFromFile {
+function Import-RegistryBackup {
     param(
         [Parameter(Mandatory)]
         [string]$FilePath
@@ -31,7 +31,7 @@ function Load-RegistryBackupFromFile {
         throw "Failed to read backup file '$FilePath'. The file is not valid JSON."
     }
 
-    return Normalize-RegistryBackup -Backup $rawBackup
+    return ConvertTo-NormalizedRegistryBackup -Backup $rawBackup
 }
 
 <#
@@ -52,7 +52,7 @@ function Load-RegistryBackupFromFile {
         ComputerName, Target, SelectedFeatures, SelectedUndoFeatures, and
         RegistryKeys properties.
 #>
-function Normalize-RegistryBackup {
+function ConvertTo-NormalizedRegistryBackup {
     param(
         [Parameter(Mandatory)]
         $Backup
@@ -93,7 +93,10 @@ function Normalize-RegistryBackup {
         }
         elseif ($normalizedTarget -like 'CurrentUser:*') {
             $targetCurrentUserName = $normalizedTarget.Substring(12)
-            if ([string]::IsNullOrWhiteSpace($targetCurrentUserName) -or
+            if (Test-RunningAsSystem) {
+                $errors.Add("Backup was made for '$targetCurrentUserName' and is user-scoped. Re-run as that user; SYSTEM cannot restore a CurrentUser backup.")
+            }
+            elseif ([string]::IsNullOrWhiteSpace($targetCurrentUserName) -or
                 -not (Test-UserNameMatch -UserNameA $targetCurrentUserName -UserNameB $env:USERNAME)) {
                  $errors.Add("Backup was made for '$targetCurrentUserName', this does not match current user '$env:USERNAME'.")
             }
@@ -176,7 +179,7 @@ function Normalize-RegistryBackup {
         registry, loading the appropriate user hive when required.
 
     .PARAMETER Backup
-        A normalized backup object (as produced by Normalize-RegistryBackup) whose
+        A normalized backup object (as produced by ConvertTo-NormalizedRegistryBackup) whose
         RegistryKeys snapshots should be restored.
 
     .OUTPUTS
@@ -190,7 +193,7 @@ function Restore-RegistryBackupState {
         $Backup
     )
 
-    $friendlyTarget = GetFriendlyRegistryBackupTarget -Target ([string]$Backup.Target)
+    $friendlyTarget = Get-FriendlyRegistryBackupTarget -Target ([string]$Backup.Target)
 
     if ($script:Params.ContainsKey("WhatIf")) {
         Write-Host "[WhatIf] Restore registry backup for $friendlyTarget" -ForegroundColor Cyan

Scripts/Features/Set-StoreSearchSuggestions.ps1

@@ -11,20 +11,20 @@
     .EXAMPLE
     DisableStoreSearchSuggestionsForAllUsers
 #>
-function DisableStoreSearchSuggestionsForAllUsers {
+function Set-StoreSearchSuggestionsDisabledForAllUsers {
     # Get path to Store app database for all users
-    $userPathString = GetUserDirectory -userName "*" -fileName "AppData\Local\Packages"
+    $userPathString = Get-UserDirectory -userName "*" -fileName "AppData\Local\Packages"
     $usersStoreDbPaths = Get-ChildItem -Path $userPathString -ErrorAction SilentlyContinue
 
     # Go through all users and disable start search suggestions
     foreach ($storeDbPath in $usersStoreDbPaths) {
-        DisableStoreSearchSuggestions -StoreAppsDatabase ($storeDbPath.FullName + "\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db")
+        Set-StoreSearchSuggestionsDisabled -StoreAppsDatabase ($storeDbPath.FullName + "\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db")
     }
 
     # Also disable start search suggestions for the default user profile
-    $defaultStoreDbPath = GetStoreAppsDatabasePathForUser -UserName "Default"
+    $defaultStoreDbPath = Get-StoreAppsDatabasePathForUser -UserName "Default"
     if ($defaultStoreDbPath) {
-        DisableStoreSearchSuggestions -StoreAppsDatabase $defaultStoreDbPath
+        Set-StoreSearchSuggestionsDisabled -StoreAppsDatabase $defaultStoreDbPath
     }
 }
 
@@ -45,7 +45,7 @@ function DisableStoreSearchSuggestionsForAllUsers {
     .EXAMPLE
     DisableStoreSearchSuggestions -StoreAppsDatabase "$env:LOCALAPPDATA\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db"
 #>
-function DisableStoreSearchSuggestions {
+function Set-StoreSearchSuggestionsDisabled {
     param (
         [Parameter(Mandatory)]
         [string]$StoreAppsDatabase
@@ -95,20 +95,20 @@ function DisableStoreSearchSuggestions {
     .EXAMPLE
     EnableStoreSearchSuggestionsForAllUsers
 #>
-function EnableStoreSearchSuggestionsForAllUsers {
+function Set-StoreSearchSuggestionsEnabledForAllUsers {
     # Get path to Store app database for all users
-    $userPathString = GetUserDirectory -userName "*" -fileName "AppData\Local\Packages"
+    $userPathString = Get-UserDirectory -userName "*" -fileName "AppData\Local\Packages"
     $usersStoreDbPaths = Get-ChildItem -Path $userPathString -ErrorAction SilentlyContinue
 
     # Go through all users and re-enable start search suggestions
     foreach ($storeDbPath in $usersStoreDbPaths) {
-        EnableStoreSearchSuggestions -StoreAppsDatabase ($storeDbPath.FullName + "\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db")
+        Set-StoreSearchSuggestionsEnabled -StoreAppsDatabase ($storeDbPath.FullName + "\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db")
     }
 
     # Also re-enable for the default user profile
-    $defaultStoreDbPath = GetStoreAppsDatabasePathForUser -UserName "Default"
+    $defaultStoreDbPath = Get-StoreAppsDatabasePathForUser -UserName "Default"
     if ($defaultStoreDbPath) {
-        EnableStoreSearchSuggestions -StoreAppsDatabase $defaultStoreDbPath
+        Set-StoreSearchSuggestionsEnabled -StoreAppsDatabase $defaultStoreDbPath
     }
 }
 
@@ -128,7 +128,7 @@ function EnableStoreSearchSuggestionsForAllUsers {
     .EXAMPLE
     EnableStoreSearchSuggestions -StoreAppsDatabase "$env:LOCALAPPDATA\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db"
 #>
-function EnableStoreSearchSuggestions {
+function Set-StoreSearchSuggestionsEnabled {
     param (
         [Parameter(Mandatory)]
         [string]$StoreAppsDatabase
@@ -201,12 +201,12 @@ function EnableStoreSearchSuggestions {
     The target username. Pass an empty string or omit to resolve for the current user.
 
     .EXAMPLE
-    GetStoreAppsDatabasePathForUser -UserName "Jeff"
+    Get-StoreAppsDatabasePathForUser -UserName "Jeff"
 
     .EXAMPLE
-    GetStoreAppsDatabasePathForUser -UserName "Default"
+    Get-StoreAppsDatabasePathForUser -UserName "Default"
 #>
-function GetStoreAppsDatabasePathForUser {
+function Get-StoreAppsDatabasePathForUser {
     param(
         [string]$UserName
     )
@@ -215,7 +215,7 @@ function GetStoreAppsDatabasePathForUser {
         return "$env:LOCALAPPDATA\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db"
     }
 
-    return (GetUserDirectory -userName $UserName -fileName "AppData\Local\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db" -exitIfPathNotFound $false)
+    return (Get-UserDirectory -userName $UserName -fileName "AppData\Local\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db" -exitIfPathNotFound $false)
 }
 
 <#
@@ -287,13 +287,13 @@ function Test-StoreSearchSuggestionsDisabled {
 function Test-StoreSearchSuggestionsDisabledForAllUsers {
     $paths = @()
 
-    $userPathString = GetUserDirectory -userName "*" -fileName "AppData\Local\Packages"
+    $userPathString = Get-UserDirectory -userName "*" -fileName "AppData\Local\Packages"
     $usersStoreDbPaths = Get-ChildItem -Path $userPathString -ErrorAction SilentlyContinue
     foreach ($storeDbPath in $usersStoreDbPaths) {
         $paths += ($storeDbPath.FullName + "\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db")
     }
 
-    $defaultStoreDbPath = GetStoreAppsDatabasePathForUser -UserName "Default"
+    $defaultStoreDbPath = Get-StoreAppsDatabasePathForUser -UserName "Default"
     if ($defaultStoreDbPath) {
         $paths += $defaultStoreDbPath
     }
@@ -309,4 +309,4 @@ function Test-StoreSearchSuggestionsDisabledForAllUsers {
     }
 
     return $true
-}
+}

Scripts/Features/Windows-OptionalFeatures.ps1

@@ -1,5 +1,5 @@
 # Enables a Windows optional feature and pipes its output to the console
-function EnableWindowsFeature {
+function Enable-WindowsFeature {
     param (
         [string]$FeatureName
     )
@@ -22,7 +22,7 @@ function EnableWindowsFeature {
 }
 
 # Disables a Windows optional feature and pipes its output to the console
-function DisableWindowsFeature {
+function Disable-WindowsFeature {
     param (
         [string]$FeatureName
     )

Scripts/FileIO/Get-ValidatedAppList.ps1

@@ -1,10 +1,10 @@
 # Returns a validated list of apps based on the provided appsList and the supported apps from Apps.json
-function ValidateAppslist {
+function Get-ValidatedAppList {
     param (
         $appsList
     )
 
-    $supportedAppsList = @(LoadAppsDetailsFromJson | ForEach-Object { @($_.AppId) }) | ForEach-Object { $_.Trim() } | Where-Object { $_.Length -gt 0 }
+    $supportedAppsList = @(Import-AppDetailsFromJson | ForEach-Object { @($_.AppId) }) | ForEach-Object { $_.Trim() } | Where-Object { $_.Length -gt 0 }
     $validatedAppsList = @()
 
     # Validate provided appsList against supportedAppsList

Scripts/FileIO/Import-AppDetailsFromJson.ps1

@@ -1,5 +1,27 @@
-# Read Apps.json and return list of app objects with optional filtering
-function LoadAppsDetailsFromJson {
+<#
+    .SYNOPSIS
+        Loads application details from Apps.json.
+
+    .DESCRIPTION
+        Reads the application definitions from Apps.json, optionally filters the
+        results to installed applications, and returns normalized app objects for
+        display and selection.
+
+    .PARAMETER OnlyInstalled
+        Filters the results to applications detected through Appx or the supplied
+        winget installation list.
+
+    .PARAMETER InstalledList
+        A pre-fetched winget installation list used when filtering installed apps.
+
+    .PARAMETER InitialCheckedFromJson
+        Sets each returned app's IsChecked value from its SelectedByDefault setting.
+
+    .OUTPUTS
+        System.Management.Automation.PSCustomObject[]
+        Application detail objects containing display, selection, and removal data.
+#>
+function Import-AppDetailsFromJson {
     param (
         [switch]$OnlyInstalled,
         [object[]]$InstalledList = $null,
@@ -17,8 +39,13 @@ function LoadAppsDetailsFromJson {
 
     foreach ($appData in $jsonContent.Apps) {
         # Handle AppId as array (could be single or multiple IDs)
-        $appIdArray = if ($appData.AppId -is [array]) { $appData.AppId } else { @($appData.AppId) }
-        $appIdArray = $appIdArray | ForEach-Object { $_.Trim() } | Where-Object { $_.length -gt 0 }
+        $appIdArray = @(
+            foreach ($rawAppId in @($appData.AppId)) {
+                if ($rawAppId -isnot [string]) { continue }
+                $normalizedAppId = $rawAppId.Trim()
+                if ($normalizedAppId.Length -gt 0) { $normalizedAppId }
+            }
+        )
         if ($appIdArray.Count -eq 0) { continue }
 
         if ($OnlyInstalled) {

Scripts/FileIO/Import-AppPresetsFromJson.ps1

@@ -1,6 +1,8 @@
-# Read Apps.json and return the list of preset objects (Name + AppIds).
-# Returns an empty array if the file cannot be read or contains no presets.
-function LoadAppPresetsFromJson {
+<#
+    .SYNOPSIS
+        Returns preset names and application IDs from Apps.json, or an empty array when unavailable.
+#>
+function Import-AppPresetsFromJson {
     try {
         $jsonContent = Get-Content -Path $script:AppsListFilePath -Raw | ConvertFrom-Json
     }

Scripts/FileIO/Import-AppsFromFile.ps1

@@ -14,7 +14,7 @@
         System.String[]. An array of app ID strings, or an empty array if the
         file does not exist or contains no selected-by-default apps.
 #>
-function LoadAppsFromFile {
+function Import-AppsFromFile {
     param (
         $appsFilePath
     )
@@ -41,6 +41,6 @@ function LoadAppsFromFile {
     } 
     catch {
         Write-Error "Unable to read apps list from file: $appsFilePath"
-        AwaitKeyToExit
+        Wait-ForKeyPress
     }
 }

Scripts/FileIO/Import-JsonFile.ps1

@@ -1,6 +1,8 @@
-# Loads a JSON file from the specified path and returns the parsed object
-# Returns $null if the file doesn't exist or if parsing fails
-function LoadJsonFile {
+<#
+    .SYNOPSIS
+        Imports a JSON file, optionally validates its version, and returns $null on failure.
+#>
+function Import-JsonFile {
     param (
         [string]$filePath,
         [string]$expectedVersion = $null,

Scripts/FileIO/Import-Settings.ps1

@@ -1,11 +1,14 @@
-# Loads settings from a JSON file and adds them to script params
-function LoadSettings {
+<#
+    .SYNOPSIS
+        Imports enabled, compatible feature settings from a JSON file into the active parameters.
+#>
+function Import-Settings {
     param (
         [string]$filePath,
         [string]$expectedVersion = "1.0"
     )
     
-    $settingsJson = LoadJsonFile -filePath $filePath -expectedVersion $expectedVersion
+    $settingsJson = Import-JsonFile -filePath $filePath -expectedVersion $expectedVersion
     
     if (-not $settingsJson -or -not $settingsJson.Settings) {
         throw "Failed to load settings from $(Split-Path $filePath -Leaf)"
@@ -29,6 +32,6 @@ function LoadSettings {
            continue
         }
         
-        AddParameter $setting.Name $setting.Value
+        Add-Parameter $setting.Name $setting.Value
     }
 }

Scripts/FileIO/Save-Settings.ps1

@@ -1,5 +1,8 @@
-# Saves the current settings, excluding control parameters, to 'LastUsedSettings.json' file
-function SaveSettings {
+<#
+    .SYNOPSIS
+        Saves active feature settings, excluding control parameters, unless running in WhatIf mode.
+#>
+function Save-Settings {
     if ($script:Params.ContainsKey("WhatIf")) {
         Write-Host "[WhatIf] Save settings to LastUsedSettings.json" -ForegroundColor Cyan
         return
@@ -21,8 +24,8 @@ function SaveSettings {
         }
     }
 
-    if (-not (SaveToFile -Config $settings -FilePath $script:SavedSettingsFilePath)) {
+    if (-not (Save-ToFile -Config $settings -FilePath $script:SavedSettingsFilePath)) {
         Write-Output ""
         Write-Host "Error: Failed to save settings to LastUsedSettings.json file" -ForegroundColor Red
     }
-}
+}

Scripts/FileIO/Save-ToFile.ps1

@@ -0,0 +1,36 @@
+<#
+    .SYNOPSIS
+        Serializes a configuration hashtable to a UTF-8 JSON file.
+
+    .PARAMETER Config
+        The configuration data to serialize.
+
+    .PARAMETER FilePath
+        The destination file path.
+
+    .PARAMETER MaxDepth
+        The maximum object depth passed to ConvertTo-Json.
+
+    .OUTPUTS
+        System.Boolean. $true when the file is written; otherwise $false.
+#>
+function Save-ToFile {
+    param (
+        [Parameter(Mandatory=$true)]
+        [hashtable]$Config,
+
+        [Parameter(Mandatory=$true)]
+        [string]$FilePath,
+
+        [Parameter(Mandatory=$false)]
+        [int]$MaxDepth = 10
+    )
+
+    try {
+        $Config | ConvertTo-Json -Depth $MaxDepth | Set-Content -Path $FilePath -Encoding UTF8
+        return $true
+    }
+    catch {
+        return $false
+    }
+}

Scripts/FileIO/SaveToFile.ps1

@@ -1,22 +0,0 @@
-# Saves configuration JSON to a file.
-# Returns $true on success, $false on failure.
-function SaveToFile {
-    param (
-        [Parameter(Mandatory=$true)]
-        [hashtable]$Config,
-
-        [Parameter(Mandatory=$true)]
-        [string]$FilePath,
-
-        [Parameter(Mandatory=$false)]
-        [int]$MaxDepth = 10
-    )
-
-    try {
-        $Config | ConvertTo-Json -Depth $MaxDepth | Set-Content -Path $FilePath -Encoding UTF8
-        return $true
-    }
-    catch {
-        return $false
-    }
-}

Scripts/GUI/Apply-SettingsToUiControls.ps1

@@ -1,6 +1,20 @@
-# Applies settings from a JSON object to UI controls (checkboxes and comboboxes)
-# Used by LoadDefaultsBtn and LoadLastUsedBtn in the UI
-function ApplySettingsToUiControls {
+<#
+    .SYNOPSIS
+        Applies enabled settings from JSON to mapped checkbox and combo-box controls.
+
+    .PARAMETER Window
+        The window that owns the mapped controls.
+
+    .PARAMETER SettingsJson
+        The settings object containing a Settings collection.
+
+    .PARAMETER UiControlMappings
+        The feature-to-control mapping used to locate and update controls.
+
+    .OUTPUTS
+        System.Boolean. $false for invalid settings input; otherwise $true.
+#>
+function Apply-SettingsToUiControls {
     param (
         $window,
         $settingsJson,

Scripts/GUI/Attach-ShiftClickBehavior.ps1

@@ -1,10 +1,20 @@
-# Attaches shift-click selection behavior to a checkbox in an apps panel
-# Parameters:
-#   - $checkbox: The checkbox to attach the behavior to
-#   - $appsPanel: The StackPanel containing checkbox items
-#   - $lastSelectedCheckboxRef: A reference to a variable storing the last clicked checkbox
-#   - $updateStatusCallback: Optional callback to update selection status
-function AttachShiftClickBehavior {
+<#
+    .SYNOPSIS
+        Attaches shift-click range-selection behavior to an application checkbox.
+
+    .PARAMETER Checkbox
+        The checkbox that receives the mouse event handler.
+
+    .PARAMETER AppsPanel
+        The panel whose visible checkboxes participate in range selection.
+
+    .PARAMETER LastSelectedCheckboxRef
+        A reference that stores the previously clicked checkbox.
+
+    .PARAMETER UpdateStatusCallback
+        An optional callback invoked after a range selection changes.
+#>
+function Attach-ShiftClickBehavior {
     param (
         [System.Windows.Controls.CheckBox]$checkbox,
         [System.Windows.Controls.StackPanel]$appsPanel,

Scripts/GUI/Get-SystemUsesDarkMode.ps1

@@ -1,5 +1,11 @@
-# Checks if the system is set to use dark mode for apps
-function GetSystemUsesDarkMode {
+<#
+    .SYNOPSIS
+        Returns whether Windows apps are configured to use dark mode.
+
+    .OUTPUTS
+        System.Boolean. $false when the personalization setting cannot be read.
+#>
+function Get-SystemUsesDarkMode {
     try {
         $personalizeKey = Get-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize'
 

Scripts/GUI/MainWindow-AppSelection.ps1

@@ -223,7 +223,7 @@ function Update-AppPresetStates {
     $script:UpdatingPresets = $true
     try {
         # Helper: count matching and checked apps, set checkbox state
-        function SetPresetState($CheckBox, [scriptblock]$MatchFilter) {
+        function Set-PresetState($CheckBox, [scriptblock]$MatchFilter) {
             $total = 0; $checked = 0
             foreach ($child in $AppsPanel.Children) {
                 if ($child -is [System.Windows.Controls.CheckBox]) {
@@ -241,15 +241,15 @@ function Update-AppPresetStates {
         $presetDefaultApps = $window.FindName('PresetDefaultApps')
         $presetLastUsed = $window.FindName('PresetLastUsed')
 
-        SetPresetState $presetDefaultApps { param($c) $c.SelectedByDefault -eq $true }
+        Set-PresetState $presetDefaultApps { param($c) $c.SelectedByDefault -eq $true }
         foreach ($jsonCb in $script:JsonPresetCheckboxes) {
             $localIds = $jsonCb.PresetAppIds
-            SetPresetState $jsonCb { param($c) (@($c.AppIds) | Where-Object { $localIds -contains $_ }).Count -gt 0 }.GetNewClosure()
+            Set-PresetState $jsonCb { param($c) (@($c.AppIds) | Where-Object { $localIds -contains $_ }).Count -gt 0 }.GetNewClosure()
         }
 
         # Last used preset: only update if it's visible (has saved apps)
         if ($presetLastUsed.Visibility -ne 'Collapsed' -and $script:SavedAppIds) {
-            SetPresetState $presetLastUsed { param($c) (@($c.AppIds) | Where-Object { $script:SavedAppIds -contains $_ }).Count -gt 0 }
+            Set-PresetState $presetLastUsed { param($c) (@($c.AppIds) | Where-Object { $script:SavedAppIds -contains $_ }).Count -gt 0 }
         }
     }
     finally {
@@ -304,7 +304,29 @@ function Find-ParentScrollViewer {
     return $null
 }
 
-function Load-AppsWithList {
+<#
+    .SYNOPSIS
+        Loads application details and adds their interactive checkboxes to the main window.
+
+    .PARAMETER Window
+        The main application window and resource owner.
+
+    .PARAMETER AppsPanel
+        The panel populated with application checkboxes.
+
+    .PARAMETER OnlyInstalledAppsBox
+        The filter control that determines whether only installed apps are loaded.
+
+    .PARAMETER LoadingAppsIndicator
+        The loading indicator shown while application details are prepared.
+
+    .PARAMETER ImportConfigBtn
+        The optional import control re-enabled after loading completes.
+
+    .PARAMETER ListOfApps
+        An optional pre-fetched list of installed WinGet applications.
+#>
+function Add-AppsToMainWindow {
     param(
         [System.Windows.Window]$Window,
         [System.Windows.Controls.Panel]$AppsPanel,
@@ -335,7 +357,7 @@ function Load-AppsWithList {
             $script:AppsListFilePath = $appsListFilePath
             . $helperScript
             . $loaderScript
-            LoadAppsDetailsFromJson -OnlyInstalled:$onlyInstalled -InstalledList $installedList -InitialCheckedFromJson:$false
+            Import-AppDetailsFromJson -OnlyInstalled:$onlyInstalled -InstalledList $installedList -InitialCheckedFromJson:$false
         } -ArgumentList $loaderScriptPath, $helperScriptPath, $appsFilePath, $ListOfApps, $onlyInstalled
     }
 
@@ -435,7 +457,7 @@ function Load-AppsWithList {
                 -AppRemovalScopeDescription $w.FindName('AppRemovalScopeDescription') `
                 -UserSelectionCombo $w.FindName('UserSelectionCombo')
         })
-        AttachShiftClickBehavior -checkbox $checkbox -appsPanel $AppsPanel `
+        Attach-ShiftClickBehavior -checkbox $checkbox -appsPanel $AppsPanel `
             -lastSelectedCheckboxRef ([ref]$script:MainWindowLastSelectedCheckbox) `
             -updateStatusCallback {
                 $w = $script:MainWindow
@@ -449,7 +471,7 @@ function Load-AppsWithList {
 
         $AppsPanel.Children.Add($checkbox) | Out-Null
 
-        if (($i + 1) % $batchSize -eq 0) { DoEvents }
+        if (($i + 1) % $batchSize -eq 0) { Invoke-DoEvents }
     }
 
     $sortArrowName = $Window.FindName('SortArrowName')
@@ -480,7 +502,26 @@ function Load-AppsWithList {
     }
 }
 
-function Load-AppsIntoMainUI {
+<#
+    .SYNOPSIS
+        Starts asynchronous loading of application checkboxes for the main window.
+
+    .PARAMETER Window
+        The main application window.
+
+    .PARAMETER AppsPanel
+        The panel that receives application checkboxes.
+
+    .PARAMETER OnlyInstalledAppsBox
+        The installed-applications filter control.
+
+    .PARAMETER LoadingAppsIndicator
+        The loading indicator shown until loading completes.
+
+    .PARAMETER ImportConfigBtn
+        The optional import control disabled while loading is in progress.
+#>
+function Initialize-MainWindowApps {
     param(
         [System.Windows.Window]$Window,
         [System.Windows.Controls.Panel]$AppsPanel,
@@ -511,7 +552,7 @@ function Load-AppsIntoMainUI {
     # Force a render so the loading indicator is visible, then schedule the
     # actual loading at Background priority so this call returns immediately.
     # This is critical when called from Add_Loaded: the window must finish
-    # its initialization before we start a nested message pump via DoEvents.
+    # its initialization before we start a nested message pump via Invoke-DoEvents.
     $Window.Dispatcher.Invoke([System.Windows.Threading.DispatcherPriority]::Render, [action] {})
     $Window.Dispatcher.BeginInvoke([System.Windows.Threading.DispatcherPriority]::Background, [action] {
             try {
@@ -519,7 +560,7 @@ function Load-AppsIntoMainUI {
 
                 if ($OnlyInstalledAppsBox.IsChecked -and ($script:WingetInstalled -eq $true)) {
                     Write-Host "Retrieving installed apps via winget..."
-                    $listOfApps = GetInstalledAppsViaWinget -TimeOut 20 -NonBlocking
+                    $listOfApps = Get-WingetInstalledApps -TimeOut 20 -NonBlocking
 
                     if ($null -eq $listOfApps) {
                         Write-Warning "WinGet returned no data (command timed out or failed)"
@@ -528,7 +569,7 @@ function Load-AppsIntoMainUI {
                     }
                 }
 
-                Load-AppsWithList -Window $Window -AppsPanel $AppsPanel -OnlyInstalledAppsBox $OnlyInstalledAppsBox `
+                Add-AppsToMainWindow -Window $Window -AppsPanel $AppsPanel -OnlyInstalledAppsBox $OnlyInstalledAppsBox `
                     -LoadingAppsIndicator $LoadingAppsIndicator -ImportConfigBtn $ImportConfigBtn -ListOfApps $listOfApps
             }
             catch {

Scripts/GUI/MainWindow-Deployment.ps1

@@ -147,7 +147,20 @@ function Invoke-ShowChangesOverview {
     Show-MessageBox -Message $message -Title 'Selected Changes' -Button 'OK' -Icon 'None' -Width 600
 }
 
-function Build-TweakPresetControlMap {
+<#
+    .SYNOPSIS
+        Builds the control values needed to apply a saved tweak preset.
+
+    .PARAMETER Window
+        The window that owns the visible tweak controls.
+
+    .PARAMETER SettingsJson
+        The saved settings object to translate into control values.
+
+    .OUTPUTS
+        System.Collections.Hashtable. Control metadata keyed by control name.
+#>
+function Get-TweakPresetControlMap {
     param(
         [System.Windows.Window]$Window,
         $SettingsJson
@@ -158,7 +171,7 @@ function Build-TweakPresetControlMap {
         return $presetMap
     }
 
-    # FeatureId -> control metadata, similar to ApplySettingsToUiControls lookup.
+    # FeatureId -> control metadata, similar to Apply-SettingsToUiControls lookup.
     $featureIdIndex = @{}
     foreach ($controlName in $script:UiControlMappings.Keys) {
         $control = $Window.FindName($controlName)
@@ -199,7 +212,20 @@ function Build-TweakPresetControlMap {
     return $presetMap
 }
 
-function Build-CategoryTweakPresetMap {
+<#
+    .SYNOPSIS
+        Builds the enabled state map for visible tweak controls in a category.
+
+    .PARAMETER Window
+        The window that owns the visible tweak controls.
+
+    .PARAMETER Category
+        The category whose mapped controls are included.
+
+    .OUTPUTS
+        System.Collections.Hashtable. Control metadata keyed by control name.
+#>
+function Get-CategoryTweakPresetMap {
     param(
         [System.Windows.Window]$Window,
         [string]$Category
@@ -375,10 +401,10 @@ function Initialize-TweakPresetSources {
         $LastUsedSettingsJson
     )
 
-    $script:DefaultTweakPresetMap = Build-TweakPresetControlMap -Window $Window -SettingsJson $DefaultSettingsJson
-    $script:LastUsedTweakPresetMap = Build-TweakPresetControlMap -Window $Window -SettingsJson $LastUsedSettingsJson
-    $script:PrivacyTweakPresetMap = Build-CategoryTweakPresetMap -Window $Window -Category 'Privacy & Suggested Content'
-    $script:AITweakPresetMap = Build-CategoryTweakPresetMap -Window $Window -Category 'AI'
+    $script:DefaultTweakPresetMap = Get-TweakPresetControlMap -Window $Window -SettingsJson $DefaultSettingsJson
+    $script:LastUsedTweakPresetMap = Get-TweakPresetControlMap -Window $Window -SettingsJson $LastUsedSettingsJson
+    $script:PrivacyTweakPresetMap = Get-CategoryTweakPresetMap -Window $Window -Category 'Privacy & Suggested Content'
+    $script:AITweakPresetMap = Get-CategoryTweakPresetMap -Window $Window -Category 'AI'
 
     $presetLastUsedTweaksBtn = $Window.FindName('PresetLastUsedTweaksBtn')
     if ($presetLastUsedTweaksBtn) {
@@ -421,7 +447,7 @@ function Update-UserSelectionDescription {
 
     switch ($UserSelectionCombo.SelectedIndex) {
         0 {
-            $currentUserName = GetUserName
+            $currentUserName = Get-UserName
             if ([string]::IsNullOrWhiteSpace($currentUserName)) {
                 $UserSelectionDescription.Text = "The currently logged-in user profile"
             }

Scripts/GUI/MainWindow-TweaksBuilder.ps1

@@ -1,13 +1,26 @@
 # MainWindow-TweaksBuilder.ps1
 # Dynamic tweaks UI construction from Features.json, tweak state management, selection clear, and search/highlight.
 
-function Build-DynamicTweaks {
+<#
+    .SYNOPSIS
+        Builds the main window's dynamic tweak controls from Features.json.
+
+    .PARAMETER Window
+        The main window whose category columns receive the generated controls.
+
+    .PARAMETER WinVersion
+        The Windows build number used for the category-icon fallback.
+
+    .NOTES
+        Initializes script-scoped control and category mappings used by the tweak UI.
+#>
+function New-DynamicTweakControls {
     param(
         [System.Windows.Window]$Window,
         [int]$WinVersion
     )
 
-    $featuresJson = LoadJsonFile -filePath $script:FeaturesFilePath -expectedVersion "1.0"
+    $featuresJson = Import-JsonFile -filePath $script:FeaturesFilePath -expectedVersion "1.0"
 
     if (-not $featuresJson) {
         throw "Unable to load Features.json file. The GUI cannot continue without feature definitions."
@@ -29,7 +42,26 @@ function Build-DynamicTweaks {
     $script:TweaksCompactMode = $null
     $script:TweaksCardsMovedFromCol2 = @()
 
-    function CreateLabeledCombo($parent, $labelText, $comboName, $items) {
+    <#
+        .SYNOPSIS
+            Creates and registers a labeled combo box or a checkbox for a tweak.
+
+        .PARAMETER Parent
+            The panel that receives the generated control.
+
+        .PARAMETER LabelText
+            The display and automation label for the tweak.
+
+        .PARAMETER ComboName
+            The name used to register the generated control.
+
+        .PARAMETER Items
+            The available tweak options; two options produce a checkbox.
+
+        .OUTPUTS
+            System.Windows.Controls.Control. The generated checkbox or combo box.
+    #>
+    function New-LabeledCombo($parent, $labelText, $comboName, $items) {
         # If only 2 items (No Change + one option), use a checkbox instead
         if ($items.Count -eq 2) {
             $checkbox = New-Object System.Windows.Controls.CheckBox
@@ -96,7 +128,17 @@ function Build-DynamicTweaks {
         return $combo
     }
 
-    function GetWikiUrlForCategory($category) {
+    <#
+        .SYNOPSIS
+            Returns the Features wiki URL for a tweak category.
+
+        .PARAMETER Category
+            The category name converted to a wiki anchor.
+
+        .OUTPUTS
+            System.String. The category URL, or the Features page for an empty category.
+    #>
+    function Get-WikiUrlForCategory($category) {
         if (-not $category) { return 'https://github.com/Raphire/Win11Debloat/wiki/Features' }
 
         $slug = $category.ToLowerInvariant()
@@ -107,7 +149,17 @@ function Build-DynamicTweaks {
         return "https://github.com/Raphire/Win11Debloat/wiki/Features#$slug"
     }
 
-    function GetOrCreateCategoryCard($categoryObj) {
+    <#
+        .SYNOPSIS
+            Returns the existing category panel or creates and registers a new one.
+
+        .PARAMETER CategoryObj
+            The category definition containing Name and Icon properties.
+
+        .OUTPUTS
+            System.Windows.Controls.StackPanel. The category's content panel.
+    #>
+    function Get-OrCreateCategoryCard($categoryObj) {
         $categoryName = $categoryObj.Name
         $categoryIcon = $categoryObj.Icon
 
@@ -152,7 +204,7 @@ function Build-DynamicTweaks {
         $helpBtn = New-Object System.Windows.Controls.Button
         $helpBtn.Content = $helpIcon
         $helpBtn.ToolTip = "Open the wiki for more info on '$categoryName' tweaks"
-        $helpBtn.Tag = (GetWikiUrlForCategory -category $categoryName)
+        $helpBtn.Tag = (Get-WikiUrlForCategory -category $categoryName)
         $helpBtn.Style = $Window.Resources['CategoryHelpLinkButtonStyle']
         $helpBtn.Add_Click({
                 param($button, $e)
@@ -289,8 +341,8 @@ function Build-DynamicTweaks {
                         if ($soleFeature.FeatureId -match '^Disable') { $opt = 'Disable' } elseif ($soleFeature.FeatureId -match '^Enable') { $opt = 'Enable' }
                         $items = @('No Change', $opt)
                         $comboName = ("Feature_{0}_Combo" -f $soleFeature.FeatureId) -replace '[^a-zA-Z0-9_]', ''
-                        if (-not $panel) { $panel = GetOrCreateCategoryCard -categoryObj $categoryObj }
-                        $combo = CreateLabeledCombo -parent $panel -labelText $soleFeature.Label -comboName $comboName -items $items
+                        if (-not $panel) { $panel = Get-OrCreateCategoryCard -categoryObj $categoryObj }
+                        $combo = New-LabeledCombo -parent $panel -labelText $soleFeature.Label -comboName $comboName -items $items
                         # attach tooltip from Features.json if present
                         if ($soleFeature.ToolTip -or $soleFeature.DisableWhenApplied -eq $true) {
                             $tooltipText = $soleFeature.ToolTip
@@ -314,8 +366,8 @@ function Build-DynamicTweaks {
 
                 $items = @('No Change') + ($filteredValues | ForEach-Object { $_.Label })
                 $comboName = 'Group_{0}Combo' -f $group.GroupId
-                if (-not $panel) { $panel = GetOrCreateCategoryCard -categoryObj $categoryObj }
-                $combo = CreateLabeledCombo -parent $panel -labelText $group.Label -comboName $comboName -items $items
+                if (-not $panel) { $panel = Get-OrCreateCategoryCard -categoryObj $categoryObj }
+                $combo = New-LabeledCombo -parent $panel -labelText $group.Label -comboName $comboName -items $items
                 # attach tooltip from UiGroups if present
                 if ($group.ToolTip) {
                     $tipBlock = New-Object System.Windows.Controls.TextBlock
@@ -335,8 +387,8 @@ function Build-DynamicTweaks {
                 if ($feature.FeatureId -match '^Disable') { $opt = 'Disable' } elseif ($feature.FeatureId -match '^Enable') { $opt = 'Enable' }
                 $items = @('No Change', $opt)
                 $comboName = ("Feature_{0}_Combo" -f $feature.FeatureId) -replace '[^a-zA-Z0-9_]', ''
-                if (-not $panel) { $panel = GetOrCreateCategoryCard -categoryObj $categoryObj }
-                $combo = CreateLabeledCombo -parent $panel -labelText $feature.Label -comboName $comboName -items $items
+                if (-not $panel) { $panel = Get-OrCreateCategoryCard -categoryObj $categoryObj }
+                $combo = New-LabeledCombo -parent $panel -labelText $feature.Label -comboName $comboName -items $items
                 # attach tooltip from Features.json if present, and include the disabled-state reason
                 if ($feature.ToolTip -or $feature.DisableWhenApplied -eq $true) {
                     $tooltipText = $feature.ToolTip
@@ -377,7 +429,7 @@ function Update-CurrentTweakSystemState {
     if (-not $script:UiControlMappings) { return }
     if (-not $script:Features) { return }
 
-    $featuresJson = LoadJsonFile -filePath $script:FeaturesFilePath -expectedVersion "1.0"
+    $featuresJson = Import-JsonFile -filePath $script:FeaturesFilePath -expectedVersion "1.0"
     if (-not $featuresJson) { return }
 
     $groupMap = @{}
@@ -423,7 +475,14 @@ function Update-CurrentTweakSystemState {
     }
 }
 
-function Load-CurrentTweakStateIntoUI {
+<#
+    .SYNOPSIS
+        Updates tweak controls to reflect the current system state.
+
+    .PARAMETER Window
+        The window that owns the generated tweak controls.
+#>
+function Set-CurrentTweakStateInUi {
     param([System.Windows.Window]$Window)
 
     Update-CurrentTweakSystemState -Window $Window -ApplyToUi:$true

Scripts/GUI/Set-WindowThemeResources.ps1

@@ -17,13 +17,13 @@
     When $true, dark theme colors are applied; when $false, light theme colors.
 
     .EXAMPLE
-    SetWindowThemeResources -window $MainWindow -usesDarkMode $true
+    Set-WindowThemeResources -window $MainWindow -usesDarkMode $true
 
     .EXAMPLE
-    SetWindowThemeResources -window $Dialog -usesDarkMode $false
+    Set-WindowThemeResources -window $Dialog -usesDarkMode $false
 #>
 # Sets resource colors for a WPF window based on dark mode preference
-function SetWindowThemeResources {
+function Set-WindowThemeResources {
     param (
         $window,
         [bool]$usesDarkMode

Scripts/GUI/Show-AboutDialog.ps1

@@ -1,3 +1,10 @@
+<#
+    .SYNOPSIS
+        Displays the themed About dialog for the application.
+
+    .PARAMETER Owner
+        The optional window that owns the dialog and its modal overlay.
+#>
 function Show-AboutDialog {
     param (
         [Parameter(Mandatory=$false)]
@@ -6,7 +13,7 @@ function Show-AboutDialog {
     
     Add-Type -AssemblyName PresentationFramework,PresentationCore,WindowsBase | Out-Null
     
-    $usesDarkMode = GetSystemUsesDarkMode
+    $usesDarkMode = Get-SystemUsesDarkMode
     
     # Determine owner window
     $ownerWindow = if ($Owner) { $Owner } else { $script:GuiWindow }
@@ -42,7 +49,7 @@ function Show-AboutDialog {
     }
 
     # Apply theme resources
-    SetWindowThemeResources -window $aboutWindow -usesDarkMode $usesDarkMode
+    Set-WindowThemeResources -window $aboutWindow -usesDarkMode $usesDarkMode
     
     # Get UI elements
     $titleBar = $aboutWindow.FindName('TitleBar')
@@ -95,4 +102,4 @@ function Show-AboutDialog {
             catch { }
         }
     }
-}
+}

Scripts/GUI/Show-AppSelectionWindow.ps1

@@ -1,8 +1,14 @@
-# Shows application selection window that allows the user to select what apps they want to remove or keep
+<#
+    .SYNOPSIS
+        Displays the application-selection dialog and records the confirmed selections.
+
+    .OUTPUTS
+        System.Nullable[System.Boolean]. The dialog result; confirmed application IDs are stored in $script:SelectedApps.
+#>
 function Show-AppSelectionWindow {
     Add-Type -AssemblyName PresentationFramework,PresentationCore,WindowsBase | Out-Null
 
-    $usesDarkMode = GetSystemUsesDarkMode
+    $usesDarkMode = Get-SystemUsesDarkMode
     
     # Show overlay if main window exists
     $overlay = $null
@@ -34,7 +40,7 @@ function Show-AppSelectionWindow {
         catch { }
     }
 
-    SetWindowThemeResources -window $window -usesDarkMode $usesDarkMode
+    Set-WindowThemeResources -window $window -usesDarkMode $usesDarkMode
 
     $appsPanel = $window.FindName('AppsPanel')
     $checkAllBox = $window.FindName('CheckAllBox')
@@ -46,8 +52,14 @@ function Show-AppSelectionWindow {
     # Track the last selected checkbox for shift-click range selection
     $script:AppSelectionWindowLastSelectedCheckbox = $null
 
-    # Loads apps into the apps UI
-    function LoadApps {
+    <#
+        .SYNOPSIS
+            Reloads the application-selection checkboxes using the current installed-apps filter.
+
+        .NOTES
+            Updates the dialog loading indicator and resets range-selection state.
+    #>
+    function Load-Apps {
         # Show loading indicator
         $loadingIndicator.Visibility = 'Visible'
         $window.Dispatcher.Invoke([System.Windows.Threading.DispatcherPriority]::Background, [action]{})
@@ -57,7 +69,7 @@ function Show-AppSelectionWindow {
 
         if ($onlyInstalledBox.IsChecked -and ($script:WingetInstalled -eq $true)) {
             # Attempt to get a list of installed apps via WinGet, times out after 10 seconds
-            $listOfApps = GetInstalledAppsViaWinget -TimeOut 10 -NonBlocking
+            $listOfApps = Get-WingetInstalledApps -TimeOut 10 -NonBlocking
             if ($null -eq $listOfApps) {
                 # Show error that the script was unable to get list of apps from WinGet
                 Show-MessageBox -Message 'Unable to load list of installed apps via WinGet.' -Title 'Error' -Button 'OK' -Icon 'Error' -Owner $window | Out-Null
@@ -65,7 +77,7 @@ function Show-AppSelectionWindow {
             }
         }
 
-        $appsToAdd = LoadAppsDetailsFromJson -OnlyInstalled:$onlyInstalledBox.IsChecked -InstalledList $listOfApps -InitialCheckedFromJson:$true
+        $appsToAdd = Import-AppDetailsFromJson -OnlyInstalled:$onlyInstalledBox.IsChecked -InstalledList $listOfApps -InitialCheckedFromJson:$true
 
         # Reset the last selected checkbox when loading a new list
         $script:AppSelectionWindowLastSelectedCheckbox = $null
@@ -82,7 +94,7 @@ function Show-AppSelectionWindow {
             $checkbox.Style = $window.Resources["AppsPanelCheckBoxStyle"]
             
             # Attach shift-click behavior for range selection
-            AttachShiftClickBehavior -checkbox $checkbox -appsPanel $appsPanel -lastSelectedCheckboxRef ([ref]$script:AppSelectionWindowLastSelectedCheckbox)
+            Attach-ShiftClickBehavior -checkbox $checkbox -appsPanel $appsPanel -lastSelectedCheckboxRef ([ref]$script:AppSelectionWindowLastSelectedCheckbox)
             
             $appsPanel.Children.Add($checkbox) | Out-Null
         }
@@ -112,8 +124,8 @@ function Show-AppSelectionWindow {
         }
     })
 
-    $onlyInstalledBox.Add_Checked({ LoadApps })
-    $onlyInstalledBox.Add_Unchecked({ LoadApps })
+    $onlyInstalledBox.Add_Checked({ Load-Apps })
+    $onlyInstalledBox.Add_Unchecked({ Load-Apps })
 
     $confirmBtn.Add_Click({
         $selectedApps = @()
@@ -130,7 +142,7 @@ function Show-AppSelectionWindow {
             return
         }
 
-        if (-not (ConfirmUnsafeAppRemoval -SelectedApps $selectedApps -Owner $window)) {
+        if (-not (Confirm-UnsafeAppRemoval -SelectedApps $selectedApps -Owner $window)) {
             return
         }
 
@@ -141,7 +153,7 @@ function Show-AppSelectionWindow {
 
     # Load apps after window is shown (allows UI to render first)
     $window.Add_ContentRendered({ 
-        $window.Dispatcher.Invoke([System.Windows.Threading.DispatcherPriority]::Background, [action]{ LoadApps }) | Out-Null
+        $window.Dispatcher.Invoke([System.Windows.Threading.DispatcherPriority]::Background, [action]{ Load-Apps }) | Out-Null
     })
 
     # Show the window and return dialog result

Scripts/GUI/Show-ApplyModal.ps1

@@ -1,14 +1,24 @@
+<#
+    .SYNOPSIS
+        Displays the modal progress window while selected changes are applied.
+
+    .PARAMETER Owner
+        The optional window that owns the modal and its overlay.
+
+    .PARAMETER InvokeRestartExplorer
+        Indicates whether the modal should run the Explorer-restart flow after applying changes.
+#>
 function Show-ApplyModal {
     param (
         [Parameter(Mandatory=$false)]
         [System.Windows.Window]$Owner = $null,
         [Parameter(Mandatory=$false)]
-        [bool]$RestartExplorer = $false
+        [bool]$InvokeRestartExplorer = $false
     )
     
     Add-Type -AssemblyName PresentationFramework,PresentationCore,WindowsBase | Out-Null
     
-    $usesDarkMode = GetSystemUsesDarkMode
+    $usesDarkMode = Get-SystemUsesDarkMode
     
     # Determine owner window
     $ownerWindow = if ($Owner) { $Owner } else { $script:GuiWindow }
@@ -44,7 +54,7 @@ function Show-ApplyModal {
     }
     
     # Apply theme resources
-    SetWindowThemeResources -window $applyWindow -usesDarkMode $usesDarkMode
+    Set-WindowThemeResources -window $applyWindow -usesDarkMode $usesDarkMode
     
     # Get UI elements
     $script:ApplyInProgressPanel = $applyWindow.FindName('ApplyInProgressPanel')
@@ -81,7 +91,7 @@ function Show-ApplyModal {
         $pct = if ($totalSteps -gt 0) { [math]::Round((($currentStep - 1) / $totalSteps) * 100) } else { 0 }
         $script:ApplyProgressBarEl.Value = $pct
         # Process pending window messages to keep UI responsive
-        DoEvents
+        Invoke-DoEvents
     }
 
     # Sub-step callback updates step name and interpolates progress bar within the current step
@@ -96,7 +106,7 @@ function Show-ApplyModal {
             $stepFraction = ($subIndex / $subCount) / $totalSteps
             $script:ApplyProgressBarEl.Value = [math]::Round(($baseProgress + $stepFraction) * 100)
         }
-        DoEvents
+        Invoke-DoEvents
     }
     
     # Run changes in background to keep UI responsive
@@ -107,8 +117,8 @@ function Show-ApplyModal {
             $registryImportFailureCount = [int]$script:RegistryImportFailures
             
             # Restart explorer if requested
-            if ($RestartExplorer -and -not $script:CancelRequested) {
-                RestartExplorer
+            if ($InvokeRestartExplorer -and -not $script:CancelRequested) {
+                Invoke-RestartExplorer
                 
                 # Wait for Explorer to finish relaunching, then reclaim focus.
                 Start-Sleep -Milliseconds 800
@@ -143,7 +153,7 @@ function Show-ApplyModal {
                 $script:ApplyCompletionTitleEl.Text = "Changes Applied"
 
                 # Show completion message with reboot instructions if any applied features require reboot
-                if ($RestartExplorer) {
+                if ($InvokeRestartExplorer) {
                     $rebootFeatures = Get-RebootFeatureLabels
 
                     if ($rebootFeatures.Count -gt 0) {

Scripts/GUI/Show-ImportExportConfigWindow.ps1

@@ -1,3 +1,7 @@
+<#
+    .SYNOPSIS
+        Shows a modal category-selection dialog for importing or exporting configuration.
+#>
 function Show-ImportExportConfigWindow {
     param (
         [System.Windows.Window]$Owner,
@@ -45,7 +49,7 @@ function Show-ImportExportConfigWindow {
     }
 
     $dlg.Owner = $Owner
-    SetWindowThemeResources -window $dlg -usesDarkMode $UsesDarkMode
+    Set-WindowThemeResources -window $dlg -usesDarkMode $UsesDarkMode
 
     # Copy the CheckBox default style from the main window so checkboxes get the themed template
     try {
@@ -308,7 +312,11 @@ function Build-CategoryDetails {
     return $details
 }
 
-function Apply-ImportedApplications {
+<#
+    .SYNOPSIS
+        Applies imported application selections to the application checkboxes.
+#>
+function Set-ImportedApplications {
     param (
         [System.Windows.Controls.Panel]$AppsPanel,
         [string[]]$AppIds
@@ -321,7 +329,11 @@ function Apply-ImportedApplications {
     }
 }
 
-function Apply-ImportedTweakSettings {
+<#
+    .SYNOPSIS
+        Applies imported tweak settings to their mapped UI controls.
+#>
+function Set-ImportedTweakSettings {
     param (
         [System.Windows.Window]$Owner,
         [hashtable]$UiControlMappings,
@@ -329,10 +341,14 @@ function Apply-ImportedTweakSettings {
     )
 
     $settingsJson = [PSCustomObject]@{ Settings = @($TweakSettings) }
-    ApplySettingsToUiControls -window $Owner -settingsJson $settingsJson -uiControlMappings $UiControlMappings
+    Apply-SettingsToUiControls -window $Owner -settingsJson $settingsJson -uiControlMappings $UiControlMappings
 }
 
-function Apply-ImportedDeploymentSettings {
+<#
+    .SYNOPSIS
+        Applies imported deployment settings to the deployment controls.
+#>
+function Set-ImportedDeploymentSettings {
     param (
         [System.Windows.Window]$Owner,
         [System.Windows.Controls.ComboBox]$UserSelectionCombo,
@@ -368,6 +384,10 @@ function Apply-ImportedDeploymentSettings {
     }
 }
 
+<#
+    .SYNOPSIS
+        Exports selected application, tweak, and deployment settings to a configuration file.
+#>
 function Export-Configuration {
     param (
         [System.Windows.Window]$Owner,
@@ -427,7 +447,7 @@ function Export-Configuration {
         return
     }
 
-    if (SaveToFile -Config $config -FilePath $saveDialog.FileName) {
+    if (Save-ToFile -Config $config -FilePath $saveDialog.FileName) {
         Write-Host "Configuration exported successfully: $($saveDialog.FileName)"
         Show-MessageBox -Message "Configuration exported successfully." -Title 'Export Configuration' -Button 'OK' -Icon 'Information' | Out-Null
     }
@@ -437,6 +457,10 @@ function Export-Configuration {
     }
 }
 
+<#
+    .SYNOPSIS
+        Imports selected application, tweak, and deployment settings from a configuration file.
+#>
 function Import-Configuration {
     param (
         [System.Windows.Window]$Owner,
@@ -462,7 +486,7 @@ function Import-Configuration {
 
     Write-Host "Importing configuration from '$($openDialog.FileName)'..."
 
-    $config = LoadJsonFile -filePath $openDialog.FileName -expectedVersion '1.0'
+    $config = Import-JsonFile -filePath $openDialog.FileName -expectedVersion '1.0'
     if (-not $config) {
         Write-Error "Failed to read configuration file '$($openDialog.FileName)'"
         Show-MessageBox -Message "Failed to read configuration file" -Title 'Invalid Config' -Button 'OK' -Icon 'Error' | Out-Null
@@ -504,7 +528,7 @@ function Import-Configuration {
         )
 
         Write-Host "Importing $($appIds.Count) app selection(s)."
-        Apply-ImportedApplications -AppsPanel $AppsPanel -AppIds $appIds
+        Set-ImportedApplications -AppsPanel $AppsPanel -AppIds $appIds
         
         if ($OnAppsImported) { 
             & $OnAppsImported
@@ -513,11 +537,11 @@ function Import-Configuration {
     if ($categories -contains 'System Tweaks' -and $config.Tweaks) {
         $tweakCount = @($config.Tweaks).Count
         Write-Host "Importing $tweakCount tweak(s)."
-        Apply-ImportedTweakSettings -Owner $Owner -UiControlMappings $UiControlMappings -TweakSettings @($config.Tweaks)
+        Set-ImportedTweakSettings -Owner $Owner -UiControlMappings $UiControlMappings -TweakSettings @($config.Tweaks)
     }
     if ($categories -contains 'Deployment Settings' -and $config.Deployment) {
         Write-Host 'Importing deployment settings.'
-        Apply-ImportedDeploymentSettings -Owner $Owner -UserSelectionCombo $UserSelectionCombo -OtherUsernameTextBox $OtherUsernameTextBox -DeploymentSettings @($config.Deployment)
+        Set-ImportedDeploymentSettings -Owner $Owner -UserSelectionCombo $UserSelectionCombo -OtherUsernameTextBox $OtherUsernameTextBox -DeploymentSettings @($config.Deployment)
     }
 
     Write-Host 'Configuration imported successfully.'

Scripts/GUI/Show-MainWindow.ps1

@@ -1,8 +1,12 @@
-function Show-MainWindow {
+<#
+    .SYNOPSIS
+        Creates and displays the main Win11Debloat window.
+#>
+function Show-MainWindow {
     Add-Type -AssemblyName PresentationFramework,PresentationCore,WindowsBase,System.Windows.Forms | Out-Null
 
     $WinVersion = Get-ItemPropertyValue 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' CurrentBuild
-    $usesDarkMode = GetSystemUsesDarkMode
+    $usesDarkMode = Get-SystemUsesDarkMode
 
     # ---- Load XAML ----
     $xaml = Get-Content -Path $script:MainWindowSchema -Raw
@@ -14,7 +18,7 @@
         $reader.Close()
     }
 
-    SetWindowThemeResources -window $window -usesDarkMode $usesDarkMode
+    Set-WindowThemeResources -window $window -usesDarkMode $usesDarkMode
 
     $mainBorder = $window.FindName('MainBorder')
     $titleBarBackground = $window.FindName('TitleBarBackground')
@@ -223,7 +227,7 @@
     if ($importConfigBtn) { $importConfigBtn.IsEnabled = $false }
 
     # ---- Build JSON-defined app presets ----
-    foreach ($preset in (LoadAppPresetsFromJson)) {
+    foreach ($preset in (Import-AppPresetsFromJson)) {
         $checkbox = New-Object System.Windows.Controls.CheckBox
         $checkbox.Content = $preset.Name
         $checkbox.IsThreeState = $true
@@ -301,8 +305,8 @@
 
     # ---- Load apps ----
     $appLoadStatusCallback = { Update-AppSelectionStatus -AppsPanel $appsPanel -AppSelectionStatus $appSelectionStatus -AppRemovalScopeCombo $appRemovalScopeCombo -AppRemovalScopeSection $appRemovalScopeSection -AppRemovalScopeDescription $appRemovalScopeDescription -UserSelectionCombo $userSelectionCombo }
-    $onlyInstalledAppsBox.Add_Checked({ Load-AppsIntoMainUI -Window $window -AppsPanel $appsPanel -OnlyInstalledAppsBox $onlyInstalledAppsBox -LoadingAppsIndicator $loadingAppsIndicator -ImportConfigBtn $importConfigBtn })
-    $onlyInstalledAppsBox.Add_Unchecked({ Load-AppsIntoMainUI -Window $window -AppsPanel $appsPanel -OnlyInstalledAppsBox $onlyInstalledAppsBox -LoadingAppsIndicator $loadingAppsIndicator -ImportConfigBtn $importConfigBtn })
+    $onlyInstalledAppsBox.Add_Checked({ Initialize-MainWindowApps -Window $window -AppsPanel $appsPanel -OnlyInstalledAppsBox $onlyInstalledAppsBox -LoadingAppsIndicator $loadingAppsIndicator -ImportConfigBtn $importConfigBtn })
+    $onlyInstalledAppsBox.Add_Unchecked({ Initialize-MainWindowApps -Window $window -AppsPanel $appsPanel -OnlyInstalledAppsBox $onlyInstalledAppsBox -LoadingAppsIndicator $loadingAppsIndicator -ImportConfigBtn $importConfigBtn })
 
     # ---- App presets popup ----
     $presetsPopup.Add_Opened({
@@ -617,9 +621,9 @@
             $ShowCurrentlyAppliedTweaksCheckBox.IsChecked = $false
         }
 
-        $defaultsJson = LoadJsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
+        $defaultsJson = Import-JsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
         if ($defaultsJson) {
-            ApplySettingsToUiControls -window $window -settingsJson $defaultsJson -uiControlMappings $script:UiControlMappings
+            Apply-SettingsToUiControls -window $window -settingsJson $defaultsJson -uiControlMappings $script:UiControlMappings
         }
 
         if ($script:IsLoadingApps) {
@@ -663,17 +667,17 @@
         $hasAppSelection = ($selectedApps.Count -gt 0)
 
         if ($selectedApps.Count -gt 0) {
-            if (-not (ConfirmUnsafeAppRemoval -SelectedApps $selectedApps -Owner $window)) { return }
+            if (-not (Confirm-UnsafeAppRemoval -SelectedApps $selectedApps -Owner $window)) { return }
 
-            AddParameter 'RemoveApps'
-            AddParameter 'Apps' ($selectedApps -join ',')
+            Add-Parameter 'RemoveApps'
+            Add-Parameter 'Apps' ($selectedApps -join ',')
 
             $selectedScopeItem = $appRemovalScopeCombo.SelectedItem
             if ($selectedScopeItem) {
                 switch ($selectedScopeItem.Content) {
-                    "All users" { AddParameter 'AppRemovalTarget' 'AllUsers' }
-                    "Current user only" { AddParameter 'AppRemovalTarget' 'CurrentUser' }
-                    "Target user only" { AddParameter 'AppRemovalTarget' ($otherUsernameTextBox.Text.Trim()) }
+                    "All users" { Add-Parameter 'AppRemovalTarget' 'AllUsers' }
+                    "Current user only" { Add-Parameter 'AppRemovalTarget' 'CurrentUser' }
+                    "Target user only" { Add-Parameter 'AppRemovalTarget' ($otherUsernameTextBox.Text.Trim()) }
                 }
             }
         }
@@ -681,7 +685,7 @@
         # Apply dynamic tweaks
         foreach ($tweakAction in @(Get-PendingTweakActions -Window $window -ShowAppliedTweaksMode:$showAppliedTweaksMode)) {
             if ($tweakAction.Action -eq 'Apply') {
-                AddParameter $tweakAction.FeatureId
+                Add-Parameter $tweakAction.FeatureId
                 $null = $selectedForwardFeatureIds.Add([string]$tweakAction.FeatureId)
                 continue
             }
@@ -695,27 +699,27 @@
 
         $restorePointCheckBox = $window.FindName('RestorePointCheckBox')
         if ($restorePointCheckBox -and $restorePointCheckBox.IsChecked) {
-            AddParameter 'CreateRestorePoint'
+            Add-Parameter 'CreateRestorePoint'
         }
 
         switch ($userSelectionCombo.SelectedIndex) {
-            0 { Write-Host "Selected user mode: current user ($(GetUserName))" }
+            0 { Write-Host "Selected user mode: current user ($(Get-UserName))" }
             1 {
                 Write-Host "Selected user mode: $($otherUsernameTextBox.Text.Trim())"
-                AddParameter User ($otherUsernameTextBox.Text.Trim())
+                Add-Parameter User ($otherUsernameTextBox.Text.Trim())
             }
             2 {
                 Write-Host "Selected user mode: default user profile (Sysprep)"
-                AddParameter Sysprep
+                Add-Parameter Sysprep
             }
         }
 
-        SaveSettings
+        Save-Settings
 
         $restartExplorerCheckBox = $window.FindName('RestartExplorerCheckBox')
         $shouldRestartExplorer = $restartExplorerCheckBox -and $restartExplorerCheckBox.IsChecked
 
-        Show-ApplyModal -Owner $window -RestartExplorer $shouldRestartExplorer
+        Show-ApplyModal -Owner $window -InvokeRestartExplorer $shouldRestartExplorer
         $window.Close()
     })
 
@@ -737,12 +741,12 @@
     $window.Add_Loaded({
         try {
             & $updateHomeContentPosition
-            Build-DynamicTweaks -Window $window -WinVersion $WinVersion
-            Load-CurrentTweakStateIntoUI -Window $window
+            New-DynamicTweakControls -Window $window -WinVersion $WinVersion
+            Set-CurrentTweakStateInUi -Window $window
             Update-TweaksResponsiveColumns -Window $window
 
-            $lastUsedSettingsJson = LoadJsonFile -filePath $script:SavedSettingsFilePath -expectedVersion "1.0" -optionalFile
-            $defaultsJson = LoadJsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
+            $lastUsedSettingsJson = Import-JsonFile -filePath $script:SavedSettingsFilePath -expectedVersion "1.0" -optionalFile
+            $defaultsJson = Import-JsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
 
             $script:SavedAppIds = Get-SavedAppIdsFromSettingsJson -SettingsJson $lastUsedSettingsJson
 
@@ -750,13 +754,13 @@
             Register-TweakPresetControlStateHandlers -Window $window
             Update-TweakPresetStates -Window $window
 
-            Load-AppsIntoMainUI -Window $window -AppsPanel $appsPanel -OnlyInstalledAppsBox $onlyInstalledAppsBox -LoadingAppsIndicator $loadingAppsIndicator -ImportConfigBtn $importConfigBtn
+            Initialize-MainWindowApps -Window $window -AppsPanel $appsPanel -OnlyInstalledAppsBox $onlyInstalledAppsBox -LoadingAppsIndicator $loadingAppsIndicator -ImportConfigBtn $importConfigBtn
 
             # Update Current User label
             if ($userSelectionCombo -and $userSelectionCombo.Items.Count -gt 0) {
                 $currentUserItem = $userSelectionCombo.Items[0]
                 if ($currentUserItem -is [System.Windows.Controls.ComboBoxItem]) {
-                    $currentUserItem.Content = "Current User ($(GetUserName))"
+                    $currentUserItem.Content = "Current User ($(Get-UserName))"
                 }
             }
 
@@ -809,8 +813,8 @@
     })
 
     # ---- Tweak presets wiring ----
-    $lastUsedSettingsJson = LoadJsonFile -filePath $script:SavedSettingsFilePath -expectedVersion "1.0" -optionalFile
-    $defaultsJson = LoadJsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
+    $lastUsedSettingsJson = Import-JsonFile -filePath $script:SavedSettingsFilePath -expectedVersion "1.0" -optionalFile
+    $defaultsJson = Import-JsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
     $script:DefaultTweakPresetMap = @{}
     $script:LastUsedTweakPresetMap = @{}
     $script:PrivacyTweakPresetMap = @{}
@@ -869,7 +873,7 @@
 
     # ---- Preload app data ----
     try {
-        $script:PreloadedAppData = LoadAppsDetailsFromJson -OnlyInstalled:$false -InstalledList $null -InitialCheckedFromJson:$false
+        $script:PreloadedAppData = Import-AppDetailsFromJson -OnlyInstalled:$false -InstalledList $null -InitialCheckedFromJson:$false
     }
     catch {
         Write-Warning "Failed to preload apps list: $_"

Scripts/GUI/Show-MessageBox.ps1

@@ -1,4 +1,7 @@
-# Shows a Windows 11 styled custom message box
+<#
+    .SYNOPSIS
+        Shows a themed Windows 11-style message box.
+#>
 function Show-MessageBox {
     param (
         [Parameter(Mandatory=$true)]
@@ -24,7 +27,7 @@ function Show-MessageBox {
     
     Add-Type -AssemblyName PresentationFramework,PresentationCore,WindowsBase | Out-Null
     
-    $usesDarkMode = GetSystemUsesDarkMode
+    $usesDarkMode = Get-SystemUsesDarkMode
     
     # Determine owner window - use provided Owner, or fall back to main GUI window
     $ownerWindow = if ($Owner) { $Owner } else { $script:GuiWindow }
@@ -69,7 +72,7 @@ function Show-MessageBox {
     }
     
     # Apply theme resources
-    SetWindowThemeResources -window $msgWindow -usesDarkMode $usesDarkMode
+    Set-WindowThemeResources -window $msgWindow -usesDarkMode $usesDarkMode
     
     # Get UI elements
     $titleText = $msgWindow.FindName('TitleText')

Scripts/GUI/Show-RestoreBackupDialog.ps1

@@ -15,7 +15,7 @@
         Hashtable
         Returns a Hashtable describing the user's choice. Possible shapes:
           RestoreRegistry  - @{ Result='RestoreRegistry'; Backup=<normalizedBackup> }
-          RestoreStartMenu - @{ Result='RestoreStartMenu'; StartMenuScope=<scope>;
+          Restore-StartMenu - @{ Result='Restore-StartMenu'; StartMenuScope=<scope>;
                                UseManualBackupFile=<bool>; BackupFilePath=<path|string> }
           Cancelled        - @{ Result='Cancelled' } (from New-RestoreDialogState)
 #>
@@ -26,7 +26,7 @@ function Show-RestoreBackupDialog {
 
     Add-Type -AssemblyName PresentationFramework,PresentationCore,WindowsBase | Out-Null
 
-    $usesDarkMode = GetSystemUsesDarkMode
+    $usesDarkMode = Get-SystemUsesDarkMode
     $ownerWindow = if ($Owner) { $Owner } else { $script:GuiWindow }
 
     $overlay = $null
@@ -67,7 +67,7 @@ function Show-RestoreBackupDialog {
     }
 
     try {
-        SetWindowThemeResources -window $window -usesDarkMode $usesDarkMode
+        Set-WindowThemeResources -window $window -usesDarkMode $usesDarkMode
     }
     catch { }
 
@@ -129,7 +129,7 @@ function Show-RestoreBackupDialog {
         param([string]$BackupFilePath)
 
         $scopeInfo = & $getStartMenuScopeInfo
-        $backupTargetText.Text = GetFriendlyRegistryBackupTarget -Target $scopeInfo.Target
+        $backupTargetText.Text = Get-FriendlyRegistryBackupTarget -Target $scopeInfo.Target
         $overviewSummaryText.Text = "This will replace the current Start Menu pinned apps layout for $($scopeInfo.SummaryText) with the selected backup."
         $backupFileText.Text = Split-Path -Path $BackupFilePath -Leaf
 
@@ -276,7 +276,7 @@ function Show-RestoreBackupDialog {
 
         $backupFileText.Text = Split-Path $SelectedBackupFilePath -Leaf
         $backupCreatedText.Text = $createdText
-        $backupTargetText.Text = GetFriendlyRegistryBackupTarget -Target ([string]$SelectedBackup.Target)
+        $backupTargetText.Text = Get-FriendlyRegistryBackupTarget -Target ([string]$SelectedBackup.Target)
         $featuresItemsControl.ItemsSource = $revertibleFeaturesList
         $overviewFeaturesSection.Visibility = if ($revertibleFeaturesList.Count -gt 0) { 'Visible' } else { 'Collapsed' }
         $reappliedFeaturesItemsControl.ItemsSource = $reappliedFeaturesList
@@ -318,7 +318,7 @@ function Show-RestoreBackupDialog {
         Write-Host "Backup file selected: $($openDialog.FileName)"
 
         try {
-            $selectedBackup = Load-RegistryBackupFromFile -FilePath $openDialog.FileName
+            $selectedBackup = Import-RegistryBackup -FilePath $openDialog.FileName
 
             if (-not (& $showRegistryOverview -SelectedBackup $selectedBackup -SelectedBackupFilePath $openDialog.FileName)) {
                 return
@@ -366,7 +366,7 @@ function Show-RestoreBackupDialog {
         }
 
         $window.Tag = @{
-            Result = 'RestoreStartMenu'
+            Result = 'Restore-StartMenu'
             StartMenuScope = $scope
             UseManualBackupFile = $useManualBackupFile
             BackupFilePath = $state.SelectedStartMenuBackupFilePath

Scripts/GUI/Show-RestoreBackupWindow.ps1

@@ -1,3 +1,7 @@
+<#
+    .SYNOPSIS
+        Shows the backup-restore dialog and performs the selected restore.
+#>
 function Show-RestoreBackupWindow {
     param(
         [System.Windows.Window]$Owner = $null
@@ -38,7 +42,7 @@ function Show-RestoreBackupWindow {
                 }
             }
         }
-        elseif ($dialogResult.Result -eq 'RestoreStartMenu') {
+        elseif ($dialogResult.Result -eq 'Restore-StartMenu') {
             $scope = $dialogResult.StartMenuScope
             $useManualBackupFile = ($dialogResult.UseManualBackupFile -eq $true)
             $backupFilePath = $null
@@ -54,10 +58,10 @@ function Show-RestoreBackupWindow {
             }
 
             $result = if ($scope -eq 'AllUsers') {
-                RestoreStartMenuForAllUsers -BackupFilePath $backupFilePath
+                Restore-StartMenuForAllUsers -BackupFilePath $backupFilePath
             }
             else {
-                RestoreStartMenu -BackupFilePath $backupFilePath
+                Restore-StartMenu -BackupFilePath $backupFilePath
             }
 
             $resultEntries = @($result)

Scripts/Helpers/Add-Parameter.ps1

@@ -1,5 +1,8 @@
-# Add parameter to script and write to file
-function AddParameter {
+<#
+    .SYNOPSIS
+        Adds or updates a value in the active parameter collection.
+#>
+function Add-Parameter {
     param (
         $parameterName,
         $value = $true

Scripts/Helpers/Apply-RegistryRegFile.ps1

@@ -39,25 +39,6 @@ function Convert-RegOperationToValueKind {
     }
 }
 
-function Remove-RegistrySubKeyTreeIfExists {
-    param(
-        [Parameter(Mandatory)]
-        [Microsoft.Win32.RegistryKey]$RootKey,
-        [Parameter(Mandatory)]
-        [string]$SubKeyPath
-    )
-
-    try {
-        $RootKey.DeleteSubKeyTree($SubKeyPath, $false)
-    }
-    catch [System.UnauthorizedAccessException], [System.Security.SecurityException] {
-        throw
-    }
-    catch {
-        # Best-effort cleanup only; missing keys are fine.
-    }
-}
-
 function Get-RegistryKeyForOperation {
     param(
         [Parameter(Mandatory)]

Scripts/Helpers/Confirm-UnsafeAppRemoval.ps1

@@ -1,7 +1,8 @@
-# Shows confirmation dialogs for apps that require extra caution before removal.
-# Returns $true if the user confirmed all warnings (or if no warnings were triggered),
-# $false if the user declined any warning.
-function ConfirmUnsafeAppRemoval {
+<#
+    .SYNOPSIS
+        Confirms removal of applications that require an extra safety warning.
+#>
+function Confirm-UnsafeAppRemoval {
     param (
         [string[]]$SelectedApps,
         $Owner = $null

Scripts/Helpers/Generate-AppsList.ps1

@@ -1,5 +1,8 @@
-# Generates a list of apps to remove based on the Apps parameter
-function GenerateAppsList {
+<#
+    .SYNOPSIS
+        Builds the validated application-removal list from the Apps parameter.
+#>
+function Generate-AppsList {
     if (-not ($script:Params["Apps"] -and $script:Params["Apps"] -is [string])) {
         return @()
     }
@@ -8,12 +11,12 @@ function GenerateAppsList {
 
     switch ($appMode) {
         'default' {
-            $appsList = LoadAppsFromFile $script:AppsListFilePath
+            $appsList = Import-AppsFromFile $script:AppsListFilePath
             return $appsList
         }
         default {
             $appsList = $script:Params["Apps"].Split(',') | ForEach-Object { $_.Trim() }
-            $validatedAppsList = ValidateAppslist $appsList
+            $validatedAppsList = Get-ValidatedAppList $appsList
             return $validatedAppsList
         }
     }

Scripts/Helpers/Get-FriendlyRegistryBackupTarget.ps1

@@ -1,4 +1,8 @@
-function GetFriendlyRegistryBackupTarget {
+<#
+    .SYNOPSIS
+        Converts a registry-backup target identifier into a user-friendly label.
+#>
+function Get-FriendlyRegistryBackupTarget {
     param(
         [AllowNull()]
         [AllowEmptyString()]
@@ -40,4 +44,4 @@ function GetFriendlyRegistryBackupTarget {
     }
 
     return $Target
-}
+}

Scripts/Helpers/Get-FriendlyTargetUserName.ps1

@@ -0,0 +1,13 @@
+<#
+    .SYNOPSIS
+        Returns a readable description of the current app-removal target.
+#>
+function Get-FriendlyTargetUserName {
+    $target = Get-TargetUserForAppRemoval
+
+    switch ($target) {
+        "AllUsers" { return "all users" }
+        "CurrentUser" { return "the current user" }
+        default { return "user $target" }
+    }
+}

Scripts/Helpers/Get-RegFileOperations.ps1

@@ -74,7 +74,10 @@ function Get-RegFileOperations {
         }
 
         $parsedValue = Convert-RegValueData -valueData $matches.valueData.Trim()
-        if (-not $parsedValue) { continue }
+        if (-not $parsedValue) {
+            Write-Warning "Skipping unsupported or malformed registry value '$valueName' in '$currentKeyPath'."
+            continue
+        }
 
         $operations += [PSCustomObject]@{
             OperationType = $parsedValue.OperationType
@@ -88,6 +91,10 @@ function Get-RegFileOperations {
     return $operations
 }
 
+<#
+    .SYNOPSIS
+        Converts a .reg value literal into an operation type, registry value type, and data.
+#>
 function Convert-RegValueData {
     param(
         [Parameter(Mandatory)]
@@ -121,8 +128,13 @@ function Convert-RegValueData {
     }
 
     if ($valueData -match '^hex(?:\((?<kind>[0-9a-fA-F]+)\))?:(?<bytes>[0-9a-fA-F,\s]+)$') {
-        $bytes = Convert-HexStringToByteArray -hexValue $matches.bytes
+        $parsedBytes = Convert-HexStringToByteArray -hexValue $matches.bytes
+        if ($null -eq $parsedBytes) {
+            return $null
+        }
+        $bytes = [byte[]]@($parsedBytes)
         $valueType = if ($matches.kind) { "Hex$($matches.kind)" } else { 'Binary' }
+
         $value = switch ($matches.kind) {
             '2' { Convert-RegistryByteArrayToString -byteData $bytes }
             '7' { Convert-RegistryByteArrayToMultiString -byteData $bytes }
@@ -150,16 +162,29 @@ function Convert-RegValueData {
     return $null
 }
 
+<#
+    .SYNOPSIS
+        Converts a comma-separated hexadecimal byte string into a byte array.
+#>
 function Convert-HexStringToByteArray {
     param(
         [Parameter(Mandatory)]
         [string]$hexValue
     )
 
-    $parts = $hexValue.Split(',') | ForEach-Object { $_.Trim() } | Where-Object { $_ }
-    return [System.Linq.Enumerable]::Select($parts, [Func[object, byte]] {
-            param($h) [System.Convert]::ToByte($h, 16)
-        }) -as [byte[]]
+    $parts = @($hexValue.Split(',') | ForEach-Object { $_.Trim() })
+    if ($parts | Where-Object { [string]::IsNullOrWhiteSpace($_) }) {
+        return $null
+    }
+
+    $bytes = New-Object byte[] $parts.Count
+    for ($i = 0; $i -lt $parts.Count; $i++) {
+        if ($parts[$i] -notmatch '^[0-9a-fA-F]{1,2}$') {
+            return $null
+        }
+        $bytes[$i] = [System.Convert]::ToByte($parts[$i], 16)
+    }
+    return ,$bytes
 }
 
 function Convert-RegistryByteArrayToString {

Scripts/Helpers/Get-TargetUserForAppRemoval.ps1

@@ -1,6 +1,6 @@
 # Target is determined from $script:Params["AppRemovalTarget"] or defaults to "AllUsers"
 # Target values: "AllUsers" (removes for all users + from image), "CurrentUser", or a specific username
-function GetTargetUserForAppRemoval {
+function Get-TargetUserForAppRemoval {
     if ($script:Params.ContainsKey("AppRemovalTarget")) {
         return $script:Params["AppRemovalTarget"]
     }

Scripts/Helpers/Get-UserDirectory.ps1

@@ -1,5 +1,5 @@
 # Returns the directory path of the specified user, exits script if user path can't be found
-function GetUserDirectory {
+function Get-UserDirectory {
     param (
         $userName,
         $fileName = "",
@@ -29,7 +29,7 @@ function GetUserDirectory {
             }
         }
 
-        $userContext = ResolveUserProfileContext -UserName $userName
+        $userContext = Resolve-UserProfileContext -UserName $userName
         $resolvedUserDirectory = if ($userContext) { $userContext.ProfilePath } else { $null }
         if ($resolvedUserDirectory) {
             $userPath = if ([string]::IsNullOrWhiteSpace($fileName)) {
@@ -46,9 +46,9 @@ function GetUserDirectory {
     }
     catch {
         Write-Error "Something went wrong when trying to find the user directory path for user $userName. Please ensure the user exists on this system"
-        AwaitKeyToExit
+        Wait-ForKeyPress
     }
 
     Write-Error "Unable to find user directory path for user $userName"
-    AwaitKeyToExit
+    Wait-ForKeyPress
 }

Scripts/Helpers/Get-UserName.ps1

@@ -0,0 +1,11 @@
+<#
+    .SYNOPSIS
+        Returns the explicitly targeted user name or the current process user name.
+#>
+function Get-UserName {
+    if ($script:Params.ContainsKey("User")) {
+        return $script:Params.Item("User")
+    }
+
+    return $env:USERNAME
+}

Scripts/Helpers/GetFriendlyTargetUserName.ps1

@@ -1,9 +0,0 @@
-function GetFriendlyTargetUserName {
-    $target = GetTargetUserForAppRemoval
-
-    switch ($target) {
-        "AllUsers" { return "all users" }
-        "CurrentUser" { return "the current user" }
-        default { return "user $target" }
-    }
-}

Scripts/Helpers/GetUserName.ps1

@@ -1,7 +0,0 @@
-function GetUserName {
-    if ($script:Params.ContainsKey("User")) {
-        return $script:Params.Item("User")
-    }
-
-    return $env:USERNAME
-}

Scripts/Helpers/Import-ConfigToParams.ps1

@@ -1,4 +1,8 @@
-function ImportConfigToParams {
+<#
+    .SYNOPSIS
+        Imports valid application, tweak, and deployment selections from a configuration JSON file into active parameters.
+#>
+function Import-ConfigToParams {
     param (
         [Parameter(Mandatory = $true)]
         [string]$ConfigPath,
@@ -22,7 +26,7 @@ function ImportConfigToParams {
         throw "Provided config file must be a .json file: $resolvedConfigPath"
     }
 
-    $configJson = LoadJsonFile -filePath $resolvedConfigPath -expectedVersion $ExpectedVersion
+    $configJson = Import-JsonFile -filePath $resolvedConfigPath -expectedVersion $ExpectedVersion
     if ($null -eq $configJson) {
         throw "Failed to read config file: $resolvedConfigPath"
     }
@@ -38,8 +42,8 @@ function ImportConfigToParams {
         )
         
         if ($appIds.Count -gt 0) {
-            AddParameter 'RemoveApps'
-            AddParameter 'Apps' ($appIds -join ',')
+            Add-Parameter 'RemoveApps'
+            Add-Parameter 'Apps' ($appIds -join ',')
             $importedItems++
         }
     }
@@ -59,7 +63,7 @@ function ImportConfigToParams {
                 continue
             }
 
-            AddParameter $setting.Name $true
+            Add-Parameter $setting.Name $true
             $importedItems++
         }
     }
@@ -73,12 +77,12 @@ function ImportConfigToParams {
         }
 
         if ($deploymentLookup.ContainsKey('CreateRestorePoint') -and [bool]$deploymentLookup['CreateRestorePoint']) {
-            AddParameter 'CreateRestorePoint'
+            Add-Parameter 'CreateRestorePoint'
             $importedItems++
         }
 
         if ($deploymentLookup.ContainsKey('RestartExplorer') -and -not [bool]$deploymentLookup['RestartExplorer']) {
-            AddParameter 'NoRestartExplorer'
+            Add-Parameter 'NoRestartExplorer'
             $importedItems++
         }
 
@@ -87,12 +91,12 @@ function ImportConfigToParams {
                 1 {
                     $otherUserName = if ($deploymentLookup.ContainsKey('OtherUsername')) { "$($deploymentLookup['OtherUsername'])".Trim() } else { '' }
                     if (-not [string]::IsNullOrWhiteSpace($otherUserName)) {
-                        AddParameter 'User' $otherUserName
+                        Add-Parameter 'User' $otherUserName
                         $importedItems++
                     }
                 }
                 2 {
-                    AddParameter 'Sysprep'
+                    Add-Parameter 'Sysprep'
                     $importedItems++
                 }
             }
@@ -101,17 +105,17 @@ function ImportConfigToParams {
         if ($deploymentLookup.ContainsKey('AppRemovalScopeIndex') -and $script:Params.ContainsKey('RemoveApps')) {
             switch ([int]$deploymentLookup['AppRemovalScopeIndex']) {
                 0 {
-                    AddParameter 'AppRemovalTarget' 'AllUsers'
+                    Add-Parameter 'AppRemovalTarget' 'AllUsers'
                     $importedItems++
                 }
                 1 {
-                    AddParameter 'AppRemovalTarget' 'CurrentUser'
+                    Add-Parameter 'AppRemovalTarget' 'CurrentUser'
                     $importedItems++
                 }
                 2 {
                     $targetUser = if ($deploymentLookup.ContainsKey('OtherUsername')) { "$($deploymentLookup['OtherUsername'])".Trim() } else { '' }
                     if (-not [string]::IsNullOrWhiteSpace($targetUser)) {
-                        AddParameter 'AppRemovalTarget' $targetUser
+                        Add-Parameter 'AppRemovalTarget' $targetUser
                         $importedItems++
                     }
                 }

Scripts/Helpers/Registry-PathHelpers.ps1

@@ -1,3 +1,7 @@
+<#
+    .SYNOPSIS
+        Normalizes a rooted registry path and returns its hive and subkey components.
+#>
 function Split-RegistryPath {
     param(
         [Parameter(Mandatory)]
@@ -51,6 +55,10 @@ function Split-RegistryPath {
     }
 }
 
+<#
+    .SYNOPSIS
+        Returns the .NET registry root key for a supported registry hive name.
+#>
 function Get-RegistryRootKey {
     param(
         [Parameter(Mandatory)]
@@ -67,6 +75,39 @@ function Get-RegistryRootKey {
     }
 }
 
+<#
+    .SYNOPSIS
+        Deletes a registry subkey tree and ignores a key that has already disappeared.
+#>
+function Remove-RegistrySubKeyTreeIfExists {
+    param(
+        [Parameter(Mandatory)]
+        $RootKey,
+        [Parameter(Mandatory)]
+        [string]$SubKeyPath
+    )
+
+    try {
+        $RootKey.DeleteSubKeyTree($SubKeyPath, $false)
+    }
+    catch {
+        $failure = $_.Exception
+        while ($failure.InnerException) {
+            $failure = $failure.InnerException
+        }
+        if ($failure -is [System.ArgumentException]) {
+            # The key can disappear between snapshot inspection and deletion.
+            return
+        }
+
+        throw
+    }
+}
+
+<#
+    .SYNOPSIS
+        Returns a feature's registry-file path, using the Sysprep layout when targeting another profile.
+#>
 function Get-RegistryFilePathForFeature {
     param(
         [Parameter(Mandatory)]

Scripts/Helpers/Resolve-UserProfilePath.ps1

@@ -12,7 +12,7 @@
     .OUTPUTS
         System.String
 #>
-function NormalizeUserLookupValue {
+function Normalize-UserLookupValue {
     param(
         [string]$Value
     )
@@ -44,12 +44,12 @@ if (-not $script:ResolvedUserSidCache) {
     .OUTPUTS
         System.String
 #>
-function GetUserLookupCacheKey {
+function Get-UserLookupCacheKey {
     param(
         [string]$Value
     )
 
-    $normalizedValue = NormalizeUserLookupValue -Value $Value
+    $normalizedValue = Normalize-UserLookupValue -Value $Value
     if ([string]::IsNullOrWhiteSpace($normalizedValue)) {
         return ''
     }
@@ -72,13 +72,13 @@ function GetUserLookupCacheKey {
     .OUTPUTS
         System.String[]
 #>
-function GetNormalizedLookupCandidates {
+function Get-NormalizedLookupCandidates {
     param(
         [string[]]$Candidates
     )
 
     $normalized = @($Candidates) |
-        ForEach-Object { NormalizeUserLookupValue -Value $_ } |
+        ForEach-Object { Normalize-UserLookupValue -Value $_ } |
         Where-Object { -not [string]::IsNullOrWhiteSpace($_) } |
         Select-Object -Unique
 
@@ -100,7 +100,7 @@ function GetNormalizedLookupCandidates {
     .OUTPUTS
         System.String
 #>
-function EscapeWqlString {
+function Escape-WqlString {
     param(
         [string]$Value
     )
@@ -126,22 +126,22 @@ function EscapeWqlString {
     .OUTPUTS
         System.String
 #>
-function GetLocalUserNameSegment {
+function Get-LocalUserNameSegment {
     param(
         [string]$UserName
     )
 
-    $normalizedName = NormalizeUserLookupValue -Value $UserName
+    $normalizedName = Normalize-UserLookupValue -Value $UserName
     if ([string]::IsNullOrWhiteSpace($normalizedName)) {
         return ''
     }
 
     if ($normalizedName.Contains('\')) {
-        return NormalizeUserLookupValue -Value (($normalizedName -split '\\')[-1])
+        return Normalize-UserLookupValue -Value (($normalizedName -split '\\')[-1])
     }
 
     if ($normalizedName.Contains('@')) {
-        return NormalizeUserLookupValue -Value (($normalizedName -split '@')[0])
+        return Normalize-UserLookupValue -Value (($normalizedName -split '@')[0])
     }
 
     return $normalizedName
@@ -165,12 +165,12 @@ function GetLocalUserNameSegment {
     .OUTPUTS
         System.String
 #>
-function ResolveNetBiosDomainName {
+function Resolve-NetBiosDomainName {
     param(
         [string]$RawDomain
     )
 
-    $trimmed = NormalizeUserLookupValue -Value $RawDomain
+    $trimmed = Normalize-UserLookupValue -Value $RawDomain
     if ([string]::IsNullOrWhiteSpace($trimmed)) {
         return ''
     }
@@ -194,7 +194,7 @@ function ResolveNetBiosDomainName {
         }
 
         if ($ntDomainInstance -and -not [string]::IsNullOrWhiteSpace($ntDomainInstance.DomainName)) {
-            $fromNtDomain = NormalizeUserLookupValue -Value $ntDomainInstance.DomainName
+            $fromNtDomain = Normalize-UserLookupValue -Value $ntDomainInstance.DomainName
             if (-not [string]::IsNullOrWhiteSpace($fromNtDomain)) {
                 return $fromNtDomain
             }
@@ -205,7 +205,7 @@ function ResolveNetBiosDomainName {
     }
 
     if ($trimmed.Contains('.')) {
-        $leaf = NormalizeUserLookupValue -Value (($trimmed -split '\.')[0])
+        $leaf = Normalize-UserLookupValue -Value (($trimmed -split '\.')[0])
         if (-not [string]::IsNullOrWhiteSpace($leaf)) {
             return $leaf
         }
@@ -221,7 +221,7 @@ function ResolveNetBiosDomainName {
     .DESCRIPTION
         Cached in script scope for the process lifetime. Returns $false on
         error or workgroup. When joined, also caches the NetBIOS domain label
-        (ResolveNetBiosDomainName) for use as a profile-folder suffix.
+        (Resolve-NetBiosDomainName) for use as a profile-folder suffix.
 
     .OUTPUTS
         System.Boolean
@@ -239,7 +239,7 @@ function Test-MachineIsDomainJoined {
         $computerSystem = Get-CimInstance -ClassName Win32_ComputerSystem -ErrorAction Stop
         if ($null -ne $computerSystem -and $computerSystem.PartOfDomain) {
             $script:MachineIsDomainJoined = $true
-            $script:MachineNetBiosDomain = ResolveNetBiosDomainName -RawDomain ([string]$computerSystem.Domain)
+            $script:MachineNetBiosDomain = Resolve-NetBiosDomainName -RawDomain ([string]$computerSystem.Domain)
         }
     }
     catch {
@@ -262,7 +262,7 @@ function Test-MachineIsDomainJoined {
     .OUTPUTS
         System.String
 #>
-function GetProfileFolderDomainSuffix {
+function Get-ProfileFolderDomainSuffix {
     if (-not (Test-MachineIsDomainJoined)) {
         return ''
     }
@@ -301,12 +301,12 @@ function GetProfileFolderDomainSuffix {
     .OUTPUTS
         System.String[]
 #>
-function GetUserNameMatchCandidates {
+function Get-UserNameMatchCandidates {
     param(
         [string]$Value
     )
 
-    $normalized = NormalizeUserLookupValue -Value $Value
+    $normalized = Normalize-UserLookupValue -Value $Value
     if ([string]::IsNullOrWhiteSpace($normalized)) {
         return @()
     }
@@ -314,13 +314,13 @@ function GetUserNameMatchCandidates {
     $candidates = New-Object 'System.Collections.Generic.List[string]'
     [void]$candidates.Add($normalized)
 
-    $localSegment = GetLocalUserNameSegment -UserName $normalized
+    $localSegment = Get-LocalUserNameSegment -UserName $normalized
     if (-not [string]::IsNullOrWhiteSpace($localSegment) -and ($localSegment -ine $normalized)) {
         [void]$candidates.Add($localSegment)
     }
 
     # Domain-suffixed forms only apply where Windows writes them.
-    $domainSuffix = GetProfileFolderDomainSuffix
+    $domainSuffix = Get-ProfileFolderDomainSuffix
     if (-not [string]::IsNullOrWhiteSpace($domainSuffix)) {
         # Prefer the local segment as the stem so DOMAIN\user still yields
         # user.CONTOSO rather than the fully qualified string.
@@ -340,7 +340,7 @@ function GetUserNameMatchCandidates {
         # (registry, backup metadata), so add that form too.
         $suffixWithDot = ".$domainSuffix"
         if ($normalized.Length -gt $suffixWithDot.Length -and $normalized.EndsWith($suffixWithDot, [System.StringComparison]::OrdinalIgnoreCase)) {
-            $bareStem = NormalizeUserLookupValue -Value ($normalized.Substring(0, $normalized.Length - $suffixWithDot.Length))
+            $bareStem = Normalize-UserLookupValue -Value ($normalized.Substring(0, $normalized.Length - $suffixWithDot.Length))
             if (-not [string]::IsNullOrWhiteSpace($bareStem)) {
                 $alreadyPresent = $false
                 foreach ($existing in $candidates) {
@@ -361,7 +361,7 @@ function GetUserNameMatchCandidates {
         Test whether a user name and a profile folder leaf share an account.
 
     .DESCRIPTION
-        Compares candidate sets (via GetUserNameMatchCandidates) instead of
+        Compares candidate sets (via Get-UserNameMatchCandidates) instead of
         raw strings, so different forms of the same account still match.
 
     .PARAMETER UserName
@@ -383,8 +383,8 @@ function Test-UserNameMatchesProfileLeaf {
         return $false
     }
 
-    $leafCandidates = @(GetUserNameMatchCandidates -Value $ProfileLeaf)
-    $userCandidates = @(GetUserNameMatchCandidates -Value $UserName)
+    $leafCandidates = @(Get-UserNameMatchCandidates -Value $ProfileLeaf)
+    $userCandidates = @(Get-UserNameMatchCandidates -Value $UserName)
 
     foreach ($leaf in $leafCandidates) {
         foreach ($user in $userCandidates) {
@@ -430,13 +430,13 @@ function Test-UserNameMatch {
 
     # Workgroup: strict equality (no suffix disambiguation available).
     if (-not (Test-MachineIsDomainJoined)) {
-        $normalizedA = NormalizeUserLookupValue -Value $UserNameA
-        $normalizedB = NormalizeUserLookupValue -Value $UserNameB
+        $normalizedA = Normalize-UserLookupValue -Value $UserNameA
+        $normalizedB = Normalize-UserLookupValue -Value $UserNameB
         return ($normalizedA -ieq $normalizedB)
     }
 
-    $candidatesA = @(GetUserNameMatchCandidates -Value $UserNameA)
-    $candidatesB = @(GetUserNameMatchCandidates -Value $UserNameB)
+    $candidatesA = @(Get-UserNameMatchCandidates -Value $UserNameA)
+    $candidatesB = @(Get-UserNameMatchCandidates -Value $UserNameB)
 
     foreach ($a in $candidatesA) {
         foreach ($b in $candidatesB) {
@@ -463,7 +463,7 @@ function Test-UserNameMatch {
     .PARAMETER Sid
         Resolved SID to cache.
 #>
-function SetResolvedUserSidCache {
+function Set-ResolvedUserSidCache {
     param(
         [string[]]$Candidates,
         [string]$Sid
@@ -474,7 +474,7 @@ function SetResolvedUserSidCache {
     }
 
     foreach ($candidate in @($Candidates)) {
-        $cacheKey = GetUserLookupCacheKey -Value $candidate
+        $cacheKey = Get-UserLookupCacheKey -Value $candidate
         if ($cacheKey) {
             $script:ResolvedUserSidCache[$cacheKey] = $Sid
         }
@@ -494,13 +494,13 @@ function SetResolvedUserSidCache {
     .OUTPUTS
         System.String
 #>
-function GetCachedResolvedUserSid {
+function Get-CachedResolvedUserSid {
     param(
         [string[]]$Candidates
     )
 
     foreach ($candidate in @($Candidates)) {
-        $cacheKey = GetUserLookupCacheKey -Value $candidate
+        $cacheKey = Get-UserLookupCacheKey -Value $candidate
         if ($cacheKey -and $script:ResolvedUserSidCache.ContainsKey($cacheKey)) {
             return $script:ResolvedUserSidCache[$cacheKey]
         }
@@ -523,7 +523,7 @@ function GetCachedResolvedUserSid {
     .OUTPUTS
         System.String
 #>
-function TryResolveSidByNtAccount {
+function Try-ResolveSidByNtAccount {
     param(
         [string]$UserName
     )
@@ -560,12 +560,12 @@ function TryResolveSidByNtAccount {
     .OUTPUTS
         System.String
 #>
-function TryResolveSidByLocalLookup {
+function Try-ResolveSidByLocalLookup {
     param(
         [string[]]$Candidates
     )
 
-    $lookupCandidates = GetNormalizedLookupCandidates -Candidates $Candidates
+    $lookupCandidates = Get-NormalizedLookupCandidates -Candidates $Candidates
     if ($lookupCandidates.Count -eq 0) {
         return $null
     }
@@ -586,8 +586,8 @@ function TryResolveSidByLocalLookup {
 
     foreach ($candidate in $lookupCandidates) {
         try {
-            $escapedCandidate = EscapeWqlString -Value $candidate
-            $escapedComputerName = EscapeWqlString -Value $env:COMPUTERNAME
+            $escapedCandidate = Escape-WqlString -Value $candidate
+            $escapedComputerName = Escape-WqlString -Value $env:COMPUTERNAME
             $filter = "LocalAccount=True AND (Name='$escapedCandidate' OR FullName='$escapedCandidate' OR Caption='$escapedComputerName\$escapedCandidate')"
             $matchingAccount = Get-CimInstance -ClassName Win32_UserAccount -Filter $filter -ErrorAction Stop | Select-Object -First 1
 
@@ -617,12 +617,12 @@ function TryResolveSidByLocalLookup {
     .OUTPUTS
         System.String
 #>
-function TryResolveSidFromProfileList {
+function Try-ResolveSidFromProfileList {
     param(
         [string[]]$Candidates
     )
 
-    $lookupCandidates = GetNormalizedLookupCandidates -Candidates $Candidates
+    $lookupCandidates = Get-NormalizedLookupCandidates -Candidates $Candidates
     if ($lookupCandidates.Count -eq 0) {
         return $null
     }
@@ -635,7 +635,7 @@ function TryResolveSidFromProfileList {
                 if ([string]::IsNullOrWhiteSpace($imagePath)) { continue }
 
                 $expandedPath = [System.Environment]::ExpandEnvironmentVariables($imagePath)
-                $leafName = NormalizeUserLookupValue -Value (Split-Path -Leaf $expandedPath)
+                $leafName = Normalize-UserLookupValue -Value (Split-Path -Leaf $expandedPath)
 
                 foreach ($candidate in $lookupCandidates) {
                     if (Test-MachineIsDomainJoined) {
@@ -680,7 +680,7 @@ function TryResolveSidFromProfileList {
     .OUTPUTS
         System.Management.Automation.PSCustomObject
 #>
-function NewResolvedUserContext {
+function New-ResolvedUserContext {
     param(
         [string]$UserName,
         [string]$UserSid,
@@ -708,12 +708,12 @@ function NewResolvedUserContext {
     .OUTPUTS
         System.String
 #>
-function GetQualifiedProcessIdentityName {
+function Get-QualifiedProcessIdentityName {
     param(
         [string]$Candidate
     )
 
-    $normalizedCandidate = NormalizeUserLookupValue -Value $Candidate
+    $normalizedCandidate = Normalize-UserLookupValue -Value $Candidate
     if ([string]::IsNullOrWhiteSpace($normalizedCandidate)) {
         return $null
     }
@@ -735,7 +735,7 @@ function GetQualifiedProcessIdentityName {
             return $null
         }
 
-        $currentLocalSegment = GetLocalUserNameSegment -UserName $currentName
+        $currentLocalSegment = Get-LocalUserNameSegment -UserName $currentName
         if (-not [string]::IsNullOrWhiteSpace($currentLocalSegment) -and $currentLocalSegment -ieq $normalizedCandidate) {
             return $currentName
         }
@@ -762,19 +762,19 @@ function GetQualifiedProcessIdentityName {
     .OUTPUTS
         System.String
 #>
-function ResolveUserSid {
+function Resolve-UserSid {
     param(
         [Parameter(Mandatory)]
         [string]$UserName
     )
 
-    $candidateUserName = NormalizeUserLookupValue -Value $UserName
+    $candidateUserName = Normalize-UserLookupValue -Value $UserName
     if ([string]::IsNullOrWhiteSpace($candidateUserName)) {
         return $null
     }
 
     $hasQualifiedIdentity = $candidateUserName.Contains('\') -or $candidateUserName.Contains('@')
-    $localNameSegment = GetLocalUserNameSegment -UserName $candidateUserName
+    $localNameSegment = Get-LocalUserNameSegment -UserName $candidateUserName
     $leafNameCandidates = @()
     if ($hasQualifiedIdentity -and -not [string]::IsNullOrWhiteSpace($localNameSegment) -and $localNameSegment -ine $candidateUserName) {
         $leafNameCandidates = @($localNameSegment)
@@ -796,7 +796,7 @@ function ResolveUserSid {
         @($candidateUserName)
     }
 
-    $cachedSid = GetCachedResolvedUserSid -Candidates $lookupCandidates
+    $cachedSid = Get-CachedResolvedUserSid -Candidates $lookupCandidates
     if ($cachedSid) {
         return $cachedSid
     }
@@ -811,12 +811,12 @@ function ResolveUserSid {
     }
     elseif (Test-MachineIsDomainJoined) {
         # Prefer process identity (authoritative), then USERDOMAIN\input.
-        $processQualifiedName = GetQualifiedProcessIdentityName -Candidate $candidateUserName
+        $processQualifiedName = Get-QualifiedProcessIdentityName -Candidate $candidateUserName
         if (-not [string]::IsNullOrWhiteSpace($processQualifiedName)) {
             [void]$qualifiedNamesToTry.Add($processQualifiedName)
         }
 
-        $domainSuffix = GetProfileFolderDomainSuffix
+        $domainSuffix = Get-ProfileFolderDomainSuffix
         if (-not [string]::IsNullOrWhiteSpace($domainSuffix)) {
             $domainQualifiedName = "$domainSuffix\$candidateUserName"
             if (-not ($qualifiedNamesToTry -contains $domainQualifiedName)) {
@@ -831,10 +831,10 @@ function ResolveUserSid {
 
     # Step 2: resolve qualified form(s) via NTAccount.Translate.
     foreach ($qualifiedName in $qualifiedNamesToTry) {
-        $resolvedSid = TryResolveSidByNtAccount -UserName $qualifiedName
+        $resolvedSid = Try-ResolveSidByNtAccount -UserName $qualifiedName
         if ($resolvedSid) {
             $allCacheKeys = @($candidateUserName) + $qualifiedNamesToTry | Select-Object -Unique
-            SetResolvedUserSidCache -Candidates $allCacheKeys -Sid $resolvedSid
+            Set-ResolvedUserSidCache -Candidates $allCacheKeys -Sid $resolvedSid
             return $resolvedSid
         }
     }
@@ -842,20 +842,20 @@ function ResolveUserSid {
     # Step 3: local SAM fallback (workgroup only; skipped on domain to avoid
     # nameshare shadowing).
     if (-not (Test-MachineIsDomainJoined)) {
-        $resolvedSid = TryResolveSidByLocalLookup -Candidates $lookupCandidates
+        $resolvedSid = Try-ResolveSidByLocalLookup -Candidates $lookupCandidates
         if ($resolvedSid) {
             $allCacheKeys = @($candidateUserName) + $qualifiedNamesToTry | Select-Object -Unique
-            SetResolvedUserSidCache -Candidates $allCacheKeys -Sid $resolvedSid
+            Set-ResolvedUserSidCache -Candidates $allCacheKeys -Sid $resolvedSid
             return $resolvedSid
         }
     }
 
     # Step 4: ProfileList leaf heuristic (last resort; disambiguates by
     # on-disk folder name, suffix-aware on domain boxes).
-    $resolvedSid = TryResolveSidFromProfileList -Candidates $profileHeuristicCandidates
+    $resolvedSid = Try-ResolveSidFromProfileList -Candidates $profileHeuristicCandidates
     if ($resolvedSid) {
         $allCacheKeys = @($candidateUserName) + $qualifiedNamesToTry | Select-Object -Unique
-        SetResolvedUserSidCache -Candidates $allCacheKeys -Sid $resolvedSid
+        Set-ResolvedUserSidCache -Candidates $allCacheKeys -Sid $resolvedSid
         return $resolvedSid
     }
 
@@ -878,13 +878,13 @@ function ResolveUserSid {
     .OUTPUTS
         System.Management.Automation.PSCustomObject
 #>
-function ResolveUserProfileContext {
+function Resolve-UserProfileContext {
     param(
         [Parameter(Mandatory)]
         [string]$UserName
     )
 
-    $candidateUserName = NormalizeUserLookupValue -Value $UserName
+    $candidateUserName = Normalize-UserLookupValue -Value $UserName
     if ([string]::IsNullOrWhiteSpace($candidateUserName)) {
         return $null
     }
@@ -902,14 +902,14 @@ function ResolveUserProfileContext {
 
             $defaultProfilePath = Join-Path $rootPath 'Default'
             if (Test-Path -LiteralPath $defaultProfilePath -PathType Container) {
-                return (NewResolvedUserContext -UserName $candidateUserName -UserSid $null -ProfilePath $defaultProfilePath)
+                return (New-ResolvedUserContext -UserName $candidateUserName -UserSid $null -ProfilePath $defaultProfilePath)
             }
         }
 
         return $null
     }
 
-    $userSid = ResolveUserSid -UserName $candidateUserName
+    $userSid = Resolve-UserSid -UserName $candidateUserName
 
     if ($userSid) {
         $sidRegistryPath = "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\$userSid"
@@ -919,7 +919,7 @@ function ResolveUserProfileContext {
                 if (-not [string]::IsNullOrWhiteSpace($registryImagePath)) {
                     $expandedPath = [System.Environment]::ExpandEnvironmentVariables($registryImagePath)
                     if (Test-Path -LiteralPath $expandedPath -PathType Container) {
-                        return (NewResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $expandedPath)
+                        return (New-ResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $expandedPath)
                     }
                 }
             }
@@ -932,7 +932,7 @@ function ResolveUserProfileContext {
             $matchingProfiles = @(Get-CimInstance -ClassName Win32_UserProfile -Filter "SID='$userSid'" -ErrorAction Stop)
             $resolvedProfile = $matchingProfiles | Where-Object { -not [string]::IsNullOrWhiteSpace($_.LocalPath) } | Select-Object -First 1
             if ($resolvedProfile -and (Test-Path -LiteralPath $resolvedProfile.LocalPath -PathType Container)) {
-                return (NewResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $resolvedProfile.LocalPath)
+                return (New-ResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $resolvedProfile.LocalPath)
             }
         }
         catch {
@@ -948,7 +948,7 @@ function ResolveUserProfileContext {
         # Exact leaf match first (common case; avoids an unnecessary scan).
         $candidateUserPath = Join-Path $rootPath $candidateUserName
         if (Test-Path -LiteralPath $candidateUserPath -PathType Container) {
-            return (NewResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $candidateUserPath)
+            return (New-ResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $candidateUserPath)
         }
 
         # Only domain-joined boxes write suffixed folders; scanning workgroup
@@ -957,7 +957,7 @@ function ResolveUserProfileContext {
             try {
                 foreach ($child in @(Get-ChildItem -LiteralPath $rootPath -Directory -ErrorAction SilentlyContinue)) {
                     if (Test-UserNameMatchesProfileLeaf -UserName $candidateUserName -ProfileLeaf $child.Name) {
-                        return (NewResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $child.FullName)
+                        return (New-ResolvedUserContext -UserName $candidateUserName -UserSid $userSid -ProfilePath $child.FullName)
                     }
                 }
             }

Scripts/Helpers/Test-ModernStandbySupport.ps1

@@ -1,5 +1,5 @@
 # Check if this machine supports S0 Modern Standby power state. Returns true if S0 Modern Standby is supported, false otherwise.
-function CheckModernStandbySupport {
+function Test-ModernStandbySupport {
     $count = 0
 
     try {

Scripts/Helpers/Test-TargetUserName.ps1

@@ -23,7 +23,7 @@ function Test-TargetUserName {
         }
     }
 
-    if (-not (CheckIfUserExists -userName $normalizedUserName)) {
+    if (-not (Test-UserProfileExists -userName $normalizedUserName)) {
         return [PSCustomObject]@{
             IsValid = $false
             UserName = $normalizedUserName

Scripts/Helpers/Test-UserProfileExists.ps1

@@ -1,4 +1,4 @@
-function CheckIfUserExists {
+function Test-UserProfileExists {
     param (
         [string]$userName
     )
@@ -10,7 +10,7 @@ function CheckIfUserExists {
     $lookupName = $userName.Trim()
 
     # Validate special characters against the local username segment (user in DOMAIN\user or user@domain).
-    $localUserName = GetLocalUserNameSegment -UserName $lookupName
+    $localUserName = Get-LocalUserNameSegment -UserName $lookupName
 
     if ($localUserName.IndexOfAny([System.IO.Path]::GetInvalidFileNameChars()) -ge 0) {
         return $false
@@ -22,7 +22,7 @@ function CheckIfUserExists {
     }
 
     try {
-        $userContext = ResolveUserProfileContext -UserName $lookupName
+        $userContext = Resolve-UserProfileContext -UserName $lookupName
         if (-not $userContext -or [string]::IsNullOrWhiteSpace($userContext.ProfilePath)) {
             return $false
         }

Scripts/Helpers/User-HiveHelpers.ps1

@@ -31,12 +31,12 @@ function Resolve-TargetUserHiveContext {
         [string]$TargetUserName
     )
 
-    $normalizedTargetUserName = NormalizeUserLookupValue -Value $TargetUserName
+    $normalizedTargetUserName = Normalize-UserLookupValue -Value $TargetUserName
     if ([string]::IsNullOrWhiteSpace($normalizedTargetUserName)) {
         throw 'Target user name for registry hive resolution is empty.'
     }
 
-    $userContext = ResolveUserProfileContext -UserName $normalizedTargetUserName
+    $userContext = Resolve-UserProfileContext -UserName $normalizedTargetUserName
     if (-not $userContext -or [string]::IsNullOrWhiteSpace([string]$userContext.ProfilePath)) {
         throw "Unable to resolve profile path for target user '$normalizedTargetUserName'."
     }

Scripts/Run-Tests.ps1

@@ -0,0 +1,49 @@
+<#
+    .SYNOPSIS
+        Runs the Win11Debloat Pester test suite locally.
+
+    .PARAMETER Bootstrap
+        Installs a compatible Pester 5 release for the current user when Pester is
+        not already available.
+#>
+[CmdletBinding()]
+param(
+    [switch]$Bootstrap
+)
+
+$ErrorActionPreference = 'Stop'
+$repositoryRoot = Split-Path -Parent $PSScriptRoot
+$testPath = Join-Path $repositoryRoot 'Tests'
+
+if (-not (Get-Module -ListAvailable -Name Pester | Where-Object { $_.Version.Major -eq 5 })) {
+    if (-not $Bootstrap) {
+        Write-Error 'Pester 5 is required. Install it with: .\Scripts\Run-Tests.ps1 -Bootstrap'
+        exit 1
+    }
+
+    try {
+        [Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12
+
+        if (-not (Get-PackageProvider -Name NuGet -ListAvailable -ErrorAction SilentlyContinue)) {
+            Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Scope CurrentUser -Force -Confirm:$false | Out-Null
+        }
+
+        Install-Module -Name Pester -RequiredVersion 5.9.0 -Scope CurrentUser -Force -AllowClobber -Confirm:$false
+    }
+    catch {
+        Write-Error "Unable to install Pester 5: $($_.Exception.Message)"
+        exit 1
+    }
+
+    if (-not (Get-Module -ListAvailable -Name Pester | Where-Object { $_.Version.Major -eq 5 })) {
+        Write-Error 'Pester 5 was not installed. Update PowerShellGet or install Pester 5 manually, then run the tests again.'
+        exit 1
+    }
+}
+
+Import-Module Pester -MinimumVersion 5.0.0 -MaximumVersion 5.999.999 -Force
+$result = Invoke-Pester -Path $testPath -Output Detailed -PassThru
+
+if ($result.Result -ne 'Passed' -or $result.FailedContainersCount -gt 0 -or $result.TotalCount -eq 0) {
+    exit 1
+}

Scripts/Threading/Invoke-DoEvents.ps1

@@ -1,6 +1,6 @@
 # Processes all pending WPF window messages (input, render, etc.) to keep the UI responsive
-# during long-running operations on the UI thread. Equivalent to Application.DoEvents().
-function DoEvents {
+# during long-running operations on the UI thread. Equivalent to Application.Invoke-DoEvents().
+function Invoke-DoEvents {
     if (-not $script:GuiWindow) { return }
     $frame = [System.Windows.Threading.DispatcherFrame]::new()
     $null = [System.Windows.Threading.Dispatcher]::CurrentDispatcher.BeginInvoke(

Scripts/Threading/Invoke-NonBlocking.ps1

@@ -31,7 +31,7 @@ function Invoke-NonBlocking {
                     $ps.Stop()
                     throw "Operation timed out after $TimeoutSeconds seconds"
                 }
-                DoEvents
+                Invoke-DoEvents
                 Start-Sleep -Milliseconds 16
             }
         }

Tests/Apply-RegistryRegFile.Tests.ps1

@@ -0,0 +1,144 @@
+BeforeAll {
+    function Invoke-WithTargetUserHive { param($TargetUserName, $ScriptBlock, $ArgumentObject) }
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Registry-PathHelpers.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-RegFileOperations.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Apply-RegistryRegFile.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Restore-RegistryApplyState.ps1')
+}
+
+Describe 'Convert-RegOperationToValueKind' {
+    It 'converts <Case> to a registry-compatible value' -ForEach @(
+        @{ Case = 'an unsigned DWord'; ValueName = $null; ValueType = 'DWord'; ValueData = [uint32]::MaxValue; ExpectedName = ''; ExpectedKind = [Microsoft.Win32.RegistryValueKind]::DWord; ExpectedValue = -1 }
+        @{ Case = 'a string value'; ValueName = 'Name'; ValueType = 'String'; ValueData = 42; ExpectedName = 'Name'; ExpectedKind = [Microsoft.Win32.RegistryValueKind]::String; ExpectedValue = '42' }
+        @{ Case = 'a binary value'; ValueName = 'Bytes'; ValueType = 'Binary'; ValueData = @(1, 255); ExpectedName = 'Bytes'; ExpectedKind = [Microsoft.Win32.RegistryValueKind]::Binary; ExpectedValue = [byte[]](1, 255) }
+    ) {
+        $result = Convert-RegOperationToValueKind -Operation ([PSCustomObject]@{
+            KeyPath = 'HK'; ValueName = $ValueName; ValueType = $ValueType; ValueData = $ValueData
+        })
+
+        $result.Name | Should -Be $ExpectedName
+        $result.Kind | Should -Be $ExpectedKind
+        $result.Value | Should -Be $ExpectedValue
+    }
+
+    It 'throws for unsupported value types' {
+        { Convert-RegOperationToValueKind -Operation ([PSCustomObject]@{ KeyPath = 'HKCU\X'; ValueType = 'Hex9'; ValueData = 1 }) } |
+            Should -Throw "Unsupported value type 'Hex9' while applying reg operation for 'HKCU\X'"
+    }
+}
+
+Describe 'Get-RegistryKeyForOperation' {
+    It 'rejects <Case>' -ForEach @(
+        @{ Case = 'an unsupported path format'; RegistryPath = 'HKCU\Software\Example'; ExpectedError = 'Unsupported registry path:*' }
+        @{ Case = 'an unsupported registry hive'; RegistryPath = 'HKEY_UNKNOWN\Software\Example'; ExpectedError = "Unsupported registry hive 'HKEY_UNKNOWN'*" }
+    ) {
+        { Get-RegistryKeyForOperation -RegistryPath $RegistryPath } | Should -Throw $ExpectedError
+    }
+}
+
+Describe 'Invoke-RegistryOperation' {
+    BeforeEach {
+        Mock Get-RegistryKeyForOperation { [PSCustomObject]@{ RootKey = [Microsoft.Win32.Registry]::CurrentUser; SubKeyPath = 'Software\Example'; Key = 'key' } }
+        Mock Remove-RegistrySubKeyTreeIfExists {}
+        Mock Invoke-RegistryDeleteValueOperation {}
+        Mock Invoke-RegistrySetValueOperation {}
+    }
+
+    It 'dispatches <Type> to <Expected>' -ForEach @(
+        @{ Type = 'DeleteKey'; Expected = 'Remove-RegistrySubKeyTreeIfExists' }
+        @{ Type = 'DeleteValue'; Expected = 'Invoke-RegistryDeleteValueOperation' }
+        @{ Type = 'SetValue'; Expected = 'Invoke-RegistrySetValueOperation' }
+    ) {
+        $operation = [PSCustomObject]@{ OperationType = $Type; KeyPath = 'HKEY_CURRENT_USER\Software\Example'; ValueName = 'Value' }
+
+        Invoke-RegistryOperation -Operation $operation -RegFilePath 'feature.reg'
+
+        Should -Invoke $Expected -Times 1 -Exactly
+    }
+
+    It 'opens keys with create=<Create> and open=<Open> for <Type>' -ForEach @(
+        @{ Type = 'DeleteKey'; Create = $false; Open = $false }
+        @{ Type = 'DeleteValue'; Create = $false; Open = $true }
+        @{ Type = 'SetValue'; Create = $true; Open = $true }
+    ) {
+        $operation = [PSCustomObject]@{ OperationType = $Type; KeyPath = 'HKEY_CURRENT_USER\Software\Example' }
+
+        Invoke-RegistryOperation -Operation $operation -RegFilePath 'feature.reg'
+
+        Should -Invoke Get-RegistryKeyForOperation -Times 1 -Exactly -ParameterFilter {
+            [bool]$CreateIfMissing -eq $Create -and [bool]$OpenKey -eq $Open
+        }
+    }
+
+    It 'rejects unknown operation types with file context' {
+        $operation = [PSCustomObject]@{ OperationType = 'Unknown'; KeyPath = 'HKEY_CURRENT_USER\Software\Example' }
+        { Invoke-RegistryOperation -Operation $operation -RegFilePath 'feature.reg' } |
+            Should -Throw "Unsupported reg operation type 'Unknown' in 'feature.reg'"
+    }
+}
+
+Describe 'Invoke-RegistryOperationsFromRegFile' {
+    BeforeEach {
+        $script:Params = @{}
+        Mock Get-RegFileOperations { @([PSCustomObject]@{ OperationType = 'SetValue'; KeyPath = 'HKCU\One' }, [PSCustomObject]@{ OperationType = 'DeleteValue'; KeyPath = 'HKCU\Two' }) }
+        Mock Invoke-RegistryOperation {}
+        Mock Write-RegistryOperationAccessDeniedWarning {}
+        Mock Write-Warning {}
+        Mock Write-Host {}
+    }
+
+    It 'honors WhatIf without dispatching operations' {
+        $script:Params = @{ WhatIf = $true }
+
+        Invoke-RegistryOperationsFromRegFile -RegFilePath 'feature.reg'
+
+        Should -Invoke Invoke-RegistryOperation -Times 0 -Exactly
+    }
+
+    It 'continues after one access-denied operation and emits a summary warning' {
+        $script:calls = 0
+        Mock Invoke-RegistryOperation {
+            $script:calls++
+            if ($script:calls -eq 1) { throw [System.UnauthorizedAccessException]::new('denied') }
+        }
+
+        { Invoke-RegistryOperationsFromRegFile -RegFilePath 'feature.reg' } | Should -Not -Throw
+        Should -Invoke Write-RegistryOperationAccessDeniedWarning -Times 1 -Exactly
+        Should -Invoke Write-Warning -Times 1 -Exactly
+    }
+
+    It 'throws when every operation is blocked by access restrictions' {
+        Mock Invoke-RegistryOperation { throw [System.Security.SecurityException]::new('blocked') }
+
+        { Invoke-RegistryOperationsFromRegFile -RegFilePath 'feature.reg' } |
+            Should -Throw "Registry fallback import could not apply any operations in 'feature.reg' because all 2 operation(s) were blocked*"
+    }
+}
+
+Describe 'Invoke-WithLoadedRestoreHive' {
+    BeforeEach { Mock Invoke-WithTargetUserHive { param($TargetUserName) $TargetUserName } }
+
+    It 'maps <Target> to <ExpectedUser>' -ForEach @(
+        @{ Target = 'DefaultUserProfile'; ExpectedUser = 'Default' }
+        @{ Target = 'User:Alice'; ExpectedUser = 'Alice' }
+    ) {
+        Invoke-WithLoadedRestoreHive -Target $Target -ScriptBlock {} | Should -Be $ExpectedUser
+    }
+
+    It 'rejects <Case>' -ForEach @(
+        @{ Case = 'an empty user target'; Target = 'User:'; ExpectedError = 'Invalid backup target format for user restore.' }
+        @{ Case = 'a current-user target'; Target = 'CurrentUser:Alice'; ExpectedError = "Unsupported backup target 'CurrentUser:Alice'." }
+    ) {
+        { Invoke-WithLoadedRestoreHive -Target $Target -ScriptBlock {} } | Should -Throw $ExpectedError
+    }
+}
+
+Describe 'Restore-RegistryKeySnapshot - validation' {
+    It 'rejects <Case> before registry mutation' -ForEach @(
+        @{ Case = 'an unsupported snapshot path'; Path = 'HKCU\Software'; ExpectedError = 'Unsupported registry path in backup:*' }
+        @{ Case = 'a root-level snapshot path'; Path = 'HKEY_CURRENT_USER'; ExpectedError = 'Unsupported root-level registry path in backup:*' }
+    ) {
+        { Restore-RegistryKeySnapshot -Snapshot ([PSCustomObject]@{ Path = $Path; Exists = $true }) } |
+            Should -Throw $ExpectedError
+    }
+}

Tests/Confirm-UnsafeAppRemoval.Tests.ps1

@@ -0,0 +1,37 @@
+BeforeAll {
+    function Show-MessageBox { param($Message, $Title, $Button, $Icon, $Owner) 'Yes' }
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Confirm-UnsafeAppRemoval.ps1')
+}
+
+Describe 'Confirm-UnsafeAppRemoval' {
+    BeforeEach {
+        $global:Silent = $false
+        Mock Show-MessageBox { 'Yes' }
+    }
+
+    AfterEach { Remove-Variable -Name Silent -Scope Global -ErrorAction SilentlyContinue }
+
+    It 'returns true without prompting for ordinary applications' {
+        Confirm-UnsafeAppRemoval -SelectedApps @('Contoso.App') | Should -BeTrue
+        Should -Invoke Show-MessageBox -Times 0 -Exactly
+    }
+
+    It 'skips all prompts in silent mode' {
+        $global:Silent = $true
+
+        Confirm-UnsafeAppRemoval -SelectedApps @('Microsoft.WindowsStore', 'Microsoft.WindowsTerminal') | Should -BeTrue
+        Should -Invoke Show-MessageBox -Times 0 -Exactly
+    }
+
+    It 'stops when Microsoft Store removal is declined' {
+        Mock Show-MessageBox { 'No' }
+
+        Confirm-UnsafeAppRemoval -SelectedApps @('Microsoft.WindowsStore', 'Microsoft.WindowsTerminal') | Should -BeFalse
+        Should -Invoke Show-MessageBox -Times 1 -Exactly
+    }
+
+    It 'requires confirmation for both dangerous applications' {
+        Confirm-UnsafeAppRemoval -SelectedApps @('Microsoft.WindowsStore', 'Microsoft.WindowsTerminal') | Should -BeTrue
+        Should -Invoke Show-MessageBox -Times 2 -Exactly
+    }
+}

Tests/Get-CurrentTweakState.Tests.ps1

@@ -0,0 +1,186 @@
+BeforeAll {
+    function Test-StoreSearchSuggestionsDisabledForAllUsers { $false }
+    function Test-StoreSearchSuggestionsDisabled { param($StoreAppsDatabase) $false }
+    function Get-StoreAppsDatabasePathForUser { param($UserName) 'store.db' }
+    function Get-UserName { 'Alice' }
+    function Test-WindowsOptionalFeatureEnabled { param($FeatureName) $false }
+    function Get-RegFileOperations { param($regFilePath) @() }
+    function Split-RegistryPath { param($path) $null }
+    function Get-RegistryRootKey { param($hiveName) $null }
+
+    function New-CurrentStateRegistryKey {
+        param([hashtable]$Values = @{}, [hashtable]$Kinds = @{})
+        $key = [PSCustomObject]@{ Values = $Values; Kinds = $Kinds; Closed = $false }
+        $key | Add-Member ScriptMethod GetValueNames { @($this.Kinds.Keys) }
+        $key | Add-Member ScriptMethod GetValueKind { param($name) $this.Kinds[$name] }
+        $key | Add-Member ScriptMethod GetValue { param($name, $defaultValue, $options) $this.Values[$name] }
+        $key | Add-Member ScriptMethod Close { $this.Closed = $true }
+        return $key
+    }
+
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Get-CurrentTweakState.ps1')
+}
+
+Describe 'Get-ExpectedRegistryValueKind' {
+    It 'maps <ValueType> to <Expected>' -ForEach @(
+        @{ ValueType = 'DWord'; Expected = [Microsoft.Win32.RegistryValueKind]::DWord }
+        @{ ValueType = 'QWord'; Expected = [Microsoft.Win32.RegistryValueKind]::QWord }
+        @{ ValueType = 'String'; Expected = [Microsoft.Win32.RegistryValueKind]::String }
+        @{ ValueType = 'Binary'; Expected = [Microsoft.Win32.RegistryValueKind]::Binary }
+        @{ ValueType = 'Hex2'; Expected = [Microsoft.Win32.RegistryValueKind]::ExpandString }
+        @{ ValueType = 'Hex7'; Expected = [Microsoft.Win32.RegistryValueKind]::MultiString }
+    ) {
+        $operation = [PSCustomObject]@{ ValueType = $ValueType }
+
+        Get-ExpectedRegistryValueKind -Operation $operation | Should -Be $Expected
+    }
+
+    It 'returns null for unsupported operation types' {
+        Get-ExpectedRegistryValueKind -Operation ([PSCustomObject]@{ ValueType = 'Hex11' }) | Should -BeNullOrEmpty
+    }
+}
+
+Describe 'Test-FeatureApplied - special features' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:Features = @{
+            DisableWidgets = [PSCustomObject]@{}
+            DisableStoreSearchSuggestions = [PSCustomObject]@{}
+            EnableWindowsSandbox = [PSCustomObject]@{}
+            EnableWindowsSubsystemForLinux = [PSCustomObject]@{}
+        }
+        Mock Get-AppxPackage { $null }
+        Mock Test-StoreSearchSuggestionsDisabledForAllUsers { $true }
+        Mock Test-StoreSearchSuggestionsDisabled { $true }
+        Mock Get-StoreAppsDatabasePathForUser { 'store.db' }
+        Mock Get-UserName { 'Alice' }
+        Mock Test-WindowsOptionalFeatureEnabled { $true }
+    }
+
+    It '<Case>' -ForEach @(
+        @{ Case = 'treats Widgets as disabled when all related packages are absent'; PresentPackage = $null; Expected = $true; ExpectedCalls = 3 }
+        @{ Case = 'treats Widgets as enabled when a related package is present'; PresentPackage = 'MicrosoftWindows.Client.WebExperience'; Expected = $false; ExpectedCalls = 2 }
+    ) {
+        Mock Get-AppxPackage { param($Name) if ($Name -eq $PresentPackage) { [PSCustomObject]@{ Name = $Name } } }
+
+        Test-FeatureApplied -FeatureId 'DisableWidgets' | Should -Be $Expected
+        Should -Invoke Get-AppxPackage -Times $ExpectedCalls -Exactly
+    }
+
+    It 'uses <Case> Store detection' -ForEach @(
+        @{ Case = 'all-user'; Params = @{ Sysprep = $true }; AllUsersCalls = 1; UserCalls = 0 }
+        @{ Case = 'user-specific'; Params = @{}; AllUsersCalls = 0; UserCalls = 1 }
+    ) {
+        $script:Params = $Params
+        Test-FeatureApplied -FeatureId 'DisableStoreSearchSuggestions' | Should -BeTrue
+        Should -Invoke Test-StoreSearchSuggestionsDisabledForAllUsers -Times $AllUsersCalls -Exactly
+        Should -Invoke Test-StoreSearchSuggestionsDisabled -Times $UserCalls -Exactly -ParameterFilter { $StoreAppsDatabase -eq 'store.db' }
+    }
+
+    It 'checks the expected optional feature for Windows Sandbox' {
+        Test-FeatureApplied -FeatureId 'EnableWindowsSandbox' | Should -BeTrue
+        Should -Invoke Test-WindowsOptionalFeatureEnabled -Times 1 -Exactly -ParameterFilter { $FeatureName -eq 'Containers-DisposableClientVM' }
+    }
+
+    It '<Case>' -ForEach @(
+        @{ Case = 'reports WSL applied when both optional features are enabled'; DisabledFeature = $null; Expected = $true }
+        @{ Case = 'reports WSL not applied when VirtualMachinePlatform is disabled'; DisabledFeature = 'VirtualMachinePlatform'; Expected = $false }
+    ) {
+        Mock Test-WindowsOptionalFeatureEnabled { param($FeatureName) $FeatureName -ne $DisabledFeature }
+        Test-FeatureApplied -FeatureId 'EnableWindowsSubsystemForLinux' | Should -Be $Expected
+    }
+}
+
+Describe 'Test-FeatureApplied - registry preconditions' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:RegfilesPath = $TestDrive
+        $script:Features = @{
+            NoRegistry = [PSCustomObject]@{ RegistryKey = '' }
+            MissingFile = [PSCustomObject]@{ RegistryKey = 'missing.reg' }
+            EmptyOperations = [PSCustomObject]@{ RegistryKey = 'empty.reg' }
+        }
+    }
+
+    It 'returns false for <Case>' -ForEach @(
+        @{ Case = 'a feature without registry data'; FeatureId = 'NoRegistry'; ParserBehavior = 'None' }
+        @{ Case = 'a missing registry file'; FeatureId = 'MissingFile'; ParserBehavior = 'None' }
+        @{ Case = 'an empty registry operation set'; FeatureId = 'EmptyOperations'; ParserBehavior = 'Empty' }
+        @{ Case = 'a registry operation parse failure'; FeatureId = 'EmptyOperations'; ParserBehavior = 'Throw' }
+    ) {
+        if ($ParserBehavior -ne 'None') {
+            '' | Set-Content -LiteralPath (Join-Path $TestDrive 'empty.reg')
+            if ($ParserBehavior -eq 'Empty') { Mock Get-RegFileOperations { @() } }
+            if ($ParserBehavior -eq 'Throw') { Mock Get-RegFileOperations { throw 'parse failed' } }
+        }
+
+        Test-FeatureApplied -FeatureId $FeatureId | Should -BeFalse
+    }
+}
+
+Describe 'Test-FeatureApplied - registry state comparison' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:RegfilesPath = $TestDrive
+        $script:Features = @{ RegistryFeature = [PSCustomObject]@{ RegistryKey = 'feature.reg' } }
+        '' | Set-Content -LiteralPath (Join-Path $TestDrive 'feature.reg')
+        Mock Split-RegistryPath { [PSCustomObject]@{ Hive = 'HKEY_CURRENT_USER'; SubKey = 'Software\Example' } }
+    }
+
+    It 'matches set values by kind and normalized unsigned data and closes the key' {
+        $key = New-CurrentStateRegistryKey -Values @{ Large = -1L } -Kinds @{ Large = [Microsoft.Win32.RegistryValueKind]::QWord }
+        $root = [PSCustomObject]@{ Key = $key }
+        $root | Add-Member ScriptMethod OpenSubKey { param($path, $writable) $this.Key }
+        Mock Get-RegistryRootKey { $root }
+        Mock Get-RegFileOperations { @([PSCustomObject]@{ OperationType = 'SetValue'; KeyPath = 'HKEY_CURRENT_USER\Software\Example'; ValueName = 'Large'; ValueType = 'QWord'; ValueData = [uint64]::MaxValue }) }
+
+        Test-FeatureApplied -FeatureId 'RegistryFeature' | Should -BeTrue
+        $key.Closed | Should -BeTrue
+    }
+
+    It 'returns false for a value-kind or data mismatch' -ForEach @(
+        @{ ActualKind = [Microsoft.Win32.RegistryValueKind]::String; ActualData = '1'; ExpectedType = 'DWord'; ExpectedData = 1 }
+        @{ ActualKind = [Microsoft.Win32.RegistryValueKind]::DWord; ActualData = 2; ExpectedType = 'DWord'; ExpectedData = 1 }
+    ) {
+        $key = New-CurrentStateRegistryKey -Values @{ Enabled = $ActualData } -Kinds @{ Enabled = $ActualKind }
+        $root = [PSCustomObject]@{ Key = $key }
+        $root | Add-Member ScriptMethod OpenSubKey { param($path, $writable) $this.Key }
+        Mock Get-RegistryRootKey { $root }
+        Mock Get-RegFileOperations { @([PSCustomObject]@{ OperationType = 'SetValue'; KeyPath = 'HKEY_CURRENT_USER\Software\Example'; ValueName = 'Enabled'; ValueType = $ExpectedType; ValueData = $ExpectedData }) }
+
+        Test-FeatureApplied -FeatureId 'RegistryFeature' | Should -BeFalse
+        $key.Closed | Should -BeTrue
+    }
+
+    It 'treats missing keys and values as successful delete operations' -ForEach @(
+        @{ OperationType = 'DeleteKey'; ReturnKey = $false }
+        @{ OperationType = 'DeleteValue'; ReturnKey = $true }
+    ) {
+        $key = New-CurrentStateRegistryKey
+        $root = [PSCustomObject]@{ Key = $key; ReturnKey = $ReturnKey }
+        $root | Add-Member ScriptMethod OpenSubKey { param($path, $writable) if ($this.ReturnKey) { $this.Key } else { $null } }
+        Mock Get-RegistryRootKey { $root }
+        Mock Get-RegFileOperations { @([PSCustomObject]@{ OperationType = $OperationType; KeyPath = 'HKEY_CURRENT_USER\Software\Example'; ValueName = 'Gone' }) }
+
+        Test-FeatureApplied -FeatureId 'RegistryFeature' | Should -BeTrue
+    }
+}
+
+Describe 'Get-CurrentGroupActiveIndex' {
+    BeforeEach { Mock Test-FeatureApplied { $false } }
+
+    It 'returns the one-based index of the first fully applied option' {
+        $group = [PSCustomObject]@{ Values = @(
+            [PSCustomObject]@{ FeatureIds = @('One', 'Missing') }
+            [PSCustomObject]@{ FeatureIds = @('Two', 'Three') }
+        ) }
+        Mock Test-FeatureApplied { param($FeatureId) $FeatureId -in @('Two', 'Three') }
+
+        Get-CurrentGroupActiveIndex -Group $group | Should -Be 2
+    }
+
+    It 'returns zero when no option is fully applied' {
+        $group = [PSCustomObject]@{ Values = @([PSCustomObject]@{ FeatureIds = @('One') }) }
+        Get-CurrentGroupActiveIndex -Group $group | Should -Be 0
+    }
+}

Tests/Get-FriendlyRegistryBackupTarget.Tests.ps1

@@ -0,0 +1,21 @@
+BeforeAll {
+    $friendlyTargetScriptPath = Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-FriendlyRegistryBackupTarget.ps1'
+    . $friendlyTargetScriptPath
+}
+
+Describe 'Get-FriendlyRegistryBackupTarget' {
+    It 'formats <Case> as <Expected>' -ForEach @(
+        @{ Case = 'a null target'; Target = $null; Expected = 'Unknown' }
+        @{ Case = 'the default profile'; Target = 'DefaultUserProfile'; Expected = 'Default user profile' }
+        @{ Case = 'the current-user marker'; Target = 'CurrentUser'; Expected = 'Current user' }
+        @{ Case = 'the all-users marker'; Target = 'AllUsers'; Expected = 'All users' }
+        @{ Case = 'a named current user'; Target = 'CurrentUser:Alice'; Expected = 'Current user (Alice)' }
+        @{ Case = 'a named target user'; Target = 'User:Bob'; Expected = 'User (Bob)' }
+    ) {
+        Get-FriendlyRegistryBackupTarget -Target $Target | Should -Be $Expected
+    }
+
+    It 'keeps unrecognized target text visible to the user' {
+        Get-FriendlyRegistryBackupTarget -Target 'Custom:Value' | Should -Be 'Custom:Value'
+    }
+}

Tests/Get-RebootFeatureLabels.Tests.ps1

@@ -0,0 +1,31 @@
+BeforeAll {
+    $rebootFeatureLabelsScriptPath = Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-RebootFeatureLabels.ps1'
+    . $rebootFeatureLabelsScriptPath
+}
+
+Describe 'Get-RebootFeatureLabels' {
+    BeforeEach {
+        $script:Params = @{
+            ApplyFeature = $true
+            NoRebootFeature = $true
+        }
+        $script:UndoParams = @{
+            UndoFeature = $true
+            ApplyFeature = $true
+        }
+        $script:Features = @{
+            ApplyFeature = [PSCustomObject]@{ RequiresReboot = $true; Label = 'Apply feature'; UndoLabel = 'Undo apply feature' }
+            UndoFeature = [PSCustomObject]@{ RequiresReboot = $true; Label = 'Undoable feature'; UndoLabel = 'Undo feature' }
+            NoRebootFeature = [PSCustomObject]@{ RequiresReboot = $false; Label = 'No reboot'; UndoLabel = 'Undo no reboot' }
+        }
+    }
+
+    It 'includes reboot-required selections once and uses undo labels for undo operations' {
+        $result = @(Get-RebootFeatureLabels)
+
+        $result | Should -HaveCount 2
+        $result | Should -Contain 'Undo apply feature'
+        $result | Should -Contain 'Undo feature'
+        $result | Should -Not -Contain 'No reboot'
+    }
+}

Tests/Get-RegFileOperations.Tests.ps1

@@ -0,0 +1,126 @@
+BeforeAll {
+    $regFileOperationsScriptPath = Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-RegFileOperations.ps1'
+    . $regFileOperationsScriptPath
+}
+
+Describe 'Convert-RegValueData' {
+    It 'parses <ValueType> as an unsigned integer' -ForEach @(
+        @{ ValueType = 'DWord'; ValueData = 'dword:ffffffff'; Expected = [uint32]::MaxValue }
+        @{ ValueType = 'QWord'; ValueData = 'qword:ffffffffffffffff'; Expected = [uint64]::MaxValue }
+    ) {
+        $result = Convert-RegValueData -valueData $ValueData
+
+        $result.OperationType | Should -Be 'SetValue'
+        $result.ValueType | Should -Be $ValueType
+        $result.ValueData | Should -Be $Expected
+    }
+
+    It 'parses registry strings and unescapes quotes and backslashes' {
+        $result = Convert-RegValueData -valueData '"C:\\Tools\\\"Quoted\""'
+
+        $result.ValueType | Should -Be 'String'
+        $result.ValueData | Should -Be 'C:\Tools\"Quoted"'
+    }
+
+    It 'parses <Case>' -ForEach @(
+        @{ Case = 'binary hex data'; ValueData = 'hex:01,ff'; ExpectedType = 'Binary'; Expected = [byte[]](1, 255) }
+        @{ Case = 'expandable-string hex data'; ValueData = 'hex(2):25,00,54,00,45,00,4d,00,50,00,25,00,00,00'; ExpectedType = 'Hex2'; Expected = '%TEMP%' }
+        @{ Case = 'multi-string hex data'; ValueData = 'hex(7):6f,00,6e,00,65,00,00,00,74,00,77,00,6f,00,00,00,00,00'; ExpectedType = 'Hex7'; Expected = @('one', 'two') }
+    ) {
+        $result = Convert-RegValueData -valueData $ValueData
+
+        $result.ValueType | Should -Be $ExpectedType
+        $result.ValueData | Should -Be $Expected
+    }
+
+    It '<Case>' -ForEach @(
+        @{ Case = 'parses a registry value deletion'; ValueData = '-'; ExpectedOperation = 'DeleteValue' }
+        @{ Case = 'ignores unsupported data'; ValueData = 'hex(b):not-hex'; ExpectedOperation = $null }
+        @{ Case = 'rejects hex data with an empty byte token'; ValueData = 'hex:01,,ff'; ExpectedOperation = $null }
+    ) {
+        $result = Convert-RegValueData -valueData $ValueData
+        if ($ExpectedOperation) {
+            $result.OperationType | Should -Be $ExpectedOperation
+            $result.ValueType | Should -BeNullOrEmpty
+        }
+        else {
+            $result | Should -BeNullOrEmpty
+        }
+    }
+}
+
+Describe 'Convert-HexStringToByteArray' {
+    It 'rejects empty and malformed hex tokens' -ForEach @('01,,ff', ',01', '01,', '01,gg') {
+        Convert-HexStringToByteArray -hexValue $_ | Should -BeNullOrEmpty
+    }
+
+    It 'converts byte arrays to registry strings and multi-strings' {
+        Convert-RegistryByteArrayToString -byteData ([byte[]](65, 0, 0, 0)) | Should -Be 'A'
+        Convert-RegistryByteArrayToMultiString -byteData ([byte[]](65, 0, 0, 0, 66, 0, 0, 0, 0, 0)) | Should -Be @('A', 'B')
+    }
+}
+
+Describe 'Get-RegFileOperations' {
+    It 'warns when it skips malformed registry value data' {
+        $regFilePath = Join-Path $TestDrive 'malformed.reg'
+        @'
+Windows Registry Editor Version 5.00
+
+[HKEY_CURRENT_USER\Software\Example]
+"Broken"=hex:01,,ff
+'@ | Set-Content -LiteralPath $regFilePath -Encoding UTF8
+
+        Mock Write-Warning {}
+        @(Get-RegFileOperations -regFilePath $regFilePath) | Should -BeNullOrEmpty
+        Should -Invoke Write-Warning -Times 1 -Exactly -ParameterFilter { $Message -like "Skipping unsupported or malformed registry value 'Broken'*" }
+    }
+
+    It 'parses key deletion, value deletion, and continued hex values' {
+        $regFilePath = Join-Path $TestDrive 'settings.reg'
+        @'
+Windows Registry Editor Version 5.00
+
+[-HKEY_CURRENT_USER\Software\Example\Removed]
+
+[HKEY_CURRENT_USER\Software\Example]
+"Enabled"=dword:00000001
+@=-
+"Bytes"=hex:01,\
+  02,03
+'@ | Set-Content -LiteralPath $regFilePath -Encoding UTF8
+
+        $operations = @(Get-RegFileOperations -regFilePath $regFilePath)
+
+        $operations.Count | Should -Be 4
+        $operations[0].OperationType | Should -Be 'DeleteKey'
+        $operations[1].ValueName | Should -Be 'Enabled'
+        $operations[1].ValueData | Should -Be 1
+        $operations[2].OperationType | Should -Be 'DeleteValue'
+        $operations[2].ValueName | Should -Be ''
+        $operations[3].ValueData | Should -Be ([byte[]](1, 2, 3))
+    }
+
+    It 'handles comments, default-value assignment, malformed lines, and deleted-key contents' {
+        $regFilePath = Join-Path $TestDrive 'edge-cases.reg'
+        @'
+Windows Registry Editor Version 5.00
+; comment
+
+[HKEY_CURRENT_USER\Software\Example]
+@="default"
+malformed line
+
+[-HKEY_CURRENT_USER\Software\Removed]
+"Ignored"="value"
+'@ | Set-Content -LiteralPath $regFilePath -Encoding UTF8
+
+        $operations = @(Get-RegFileOperations -regFilePath $regFilePath)
+
+        $operations | Should -HaveCount 2
+        $operations[0].OperationType | Should -Be 'SetValue'
+        $operations[0].ValueName | Should -Be ''
+        $operations[0].ValueData | Should -Be 'default'
+        $operations[1].OperationType | Should -Be 'DeleteKey'
+    }
+
+}

Tests/Get-TargetUserForAppRemoval.Tests.ps1

@@ -0,0 +1,13 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-TargetUserForAppRemoval.ps1')
+}
+
+Describe 'Get-TargetUserForAppRemoval' {
+    It '<Case>' -ForEach @(
+        @{ Case = 'defaults to all users'; Params = @{}; Expected = 'AllUsers' }
+        @{ Case = 'returns an explicit target unchanged'; Params = @{ AppRemovalTarget = 'Alice' }; Expected = 'Alice' }
+    ) {
+        $script:Params = $Params
+        Get-TargetUserForAppRemoval | Should -Be $Expected
+    }
+}

Tests/Import-ConfigToParams.Tests.ps1

@@ -0,0 +1,38 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-JsonFile.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Add-Parameter.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Import-ConfigToParams.ps1')
+    $script:ConfigFixturePath = Join-Path $PSScriptRoot 'TestData\JsonFileLoading\ExportedConfig.WithSettings.json'
+}
+
+Describe 'Import-ConfigToParams' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:ModernStandbySupported = $false
+        $script:Features = @{}
+        foreach ($featureId in @(
+            'DisableSettings365Ads', 'DisableSnapAssist', 'EnableDarkMode', 'ShowSearchBoxTb',
+            'DisableTelemetry', 'DisableWidgets', 'DisableLockscreenTips', 'DisableSnapLayouts',
+            'DisableAISvcAutoStart', 'DisableMouseAcceleration', 'DisableCopilot', 'DisableRecall'
+        )) {
+            $script:Features[$featureId] = [PSCustomObject]@{ FeatureId = $featureId; MinVersion = $null; MaxVersion = $null }
+        }
+    }
+
+    It 'loads the selected tweaks and deployment settings from an exported config file' {
+        $result = Import-ConfigToParams -ConfigPath $script:ConfigFixturePath -CurrentBuild 22631
+
+        $result | Should -Be (Resolve-Path -LiteralPath $script:ConfigFixturePath).Path
+        foreach ($featureId in @(
+            'DisableSettings365Ads', 'DisableSnapAssist', 'EnableDarkMode', 'ShowSearchBoxTb',
+            'DisableTelemetry', 'DisableWidgets', 'DisableLockscreenTips', 'DisableSnapLayouts',
+            'DisableAISvcAutoStart', 'DisableMouseAcceleration', 'DisableCopilot', 'DisableRecall'
+        )) {
+            $script:Params[$featureId] | Should -BeTrue
+        }
+        $script:Params['CreateRestorePoint'] | Should -BeTrue
+        $script:Params['NoRestartExplorer'] | Should -BeTrue
+        $script:Params.ContainsKey('User') | Should -BeFalse
+        $script:Params.ContainsKey('AppRemovalTarget') | Should -BeFalse
+    }
+}

Tests/Import-JsonFile.Tests.ps1

@@ -0,0 +1,45 @@
+BeforeAll {
+    $importJsonFileScriptPath = Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-JsonFile.ps1'
+    $script:FixturePath = Join-Path $PSScriptRoot 'TestData\JsonFileLoading'
+    . $importJsonFileScriptPath
+}
+
+Describe 'Import-JsonFile' {
+    BeforeEach {
+        Mock Write-Error {}
+    }
+
+    It 'loads valid JSON with the expected version' {
+        $result = Import-JsonFile -filePath (Join-Path $script:FixturePath 'Config.Valid.json') -expectedVersion '1.0'
+
+        $result.Name | Should -Be 'Example configuration'
+    }
+
+    It 'parses the <Kind> settings fixture' -ForEach @(
+        @{ Kind = 'default'; FileName = 'DefaultSettings.Valid.json' }
+        @{ Kind = 'last-used'; FileName = 'LastUsedSettings.Valid.json' }
+    ) {
+        $result = Import-JsonFile -filePath (Join-Path $script:FixturePath $FileName) -expectedVersion '1.0'
+
+        $result.Settings | Should -Not -BeNullOrEmpty
+        $result.Settings[0].Name | Should -Be 'Supported'
+    }
+
+    It 'returns null and reports an error for <Case>' -ForEach @(
+        @{ Case = 'a version mismatch'; FileName = 'Config.VersionMismatch.json'; ExpectedVersion = '1.0'; Optional = $false; Error = 'version mismatch' }
+        @{ Case = 'invalid JSON'; FileName = 'Config.Invalid.json'; ExpectedVersion = $null; Optional = $false; Error = 'Failed to parse JSON file' }
+    ) {
+        $filePath = Join-Path $script:FixturePath $FileName
+        $result = Import-JsonFile -filePath $filePath -expectedVersion $ExpectedVersion -optionalFile:$Optional
+
+        $result | Should -BeNullOrEmpty
+        Should -Invoke Write-Error -Times 1 -Exactly -ParameterFilter { $Message -match $Error }
+    }
+
+    It 'returns null without an error for an optional missing last-used settings file' {
+        $result = Import-JsonFile -filePath (Join-Path $TestDrive 'LastUsedSettings.json') -expectedVersion '1.0' -optionalFile
+
+        $result | Should -BeNullOrEmpty
+        Should -Invoke Write-Error -Times 0 -Exactly
+    }
+}

Tests/Import-RegistryFile.Tests.ps1

@@ -0,0 +1,67 @@
+BeforeAll {
+    function Get-RegistryFilePathForFeature { param($RegistryKey) $RegistryKey }
+    function Invoke-RegistryOperationsFromRegFile { param($RegFilePath) }
+    function Invoke-WithTargetUserHive { param($TargetUserName, $ScriptBlock, $ArgumentObject, [switch]$PassHiveContext) }
+    function Invoke-NonBlocking { param($ScriptBlock, $ArgumentList) }
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Import-RegistryFile.ps1')
+}
+
+Describe 'Import-RegistryFile' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:RegistryImportFailures = 0
+        $script:regPath = Join-Path $TestDrive 'feature.reg'
+        '' | Set-Content -LiteralPath $script:regPath
+        Mock Get-RegistryFilePathForFeature { $script:regPath }
+        Mock Invoke-RegistryOperationsFromRegFile {}
+        Mock Invoke-WithTargetUserHive {}
+        Mock Invoke-NonBlocking { [PSCustomObject]@{ Output = @(); ExitCode = 0; Error = $null } }
+        Mock Write-Host {}
+        Mock Write-Warning {}
+    }
+
+    It 'throws and increments the failure count when the registry file is missing' {
+        Mock Get-RegistryFilePathForFeature { Join-Path $TestDrive 'missing.reg' }
+        { Import-RegistryFile -message 'Apply' -path 'missing.reg' } | Should -Throw 'Unable to find registry file:*'
+        $script:RegistryImportFailures | Should -Be 1
+        Should -Invoke Invoke-NonBlocking -Times 0 -Exactly
+    }
+
+    It 'uses the PowerShell writer only in WhatIf mode' {
+        $script:Params = @{ WhatIf = $true }
+        Import-RegistryFile -message 'Apply' -path 'feature.reg'
+        Should -Invoke Invoke-RegistryOperationsFromRegFile -Times 1 -Exactly -ParameterFilter { $RegFilePath -eq $script:regPath }
+        Should -Invoke Invoke-NonBlocking -Times 0 -Exactly
+    }
+
+    It 'uses the PowerShell writer for an already-loaded target-user hive' {
+        $script:Params = @{ User = 'Alice' }
+        Mock Invoke-WithTargetUserHive {
+            param($TargetUserName, $ScriptBlock, $ArgumentObject, $PassHiveContext)
+            & $ScriptBlock $ArgumentObject ([PSCustomObject]@{ WasAlreadyLoaded = $true })
+        }
+
+        Import-RegistryFile -message 'Apply' -path 'feature.reg'
+
+        Should -Invoke Invoke-WithTargetUserHive -Times 1 -Exactly -ParameterFilter { $TargetUserName -eq 'Alice' -and $PassHiveContext }
+        Should -Invoke Invoke-RegistryOperationsFromRegFile -Times 1 -Exactly
+        Should -Invoke Invoke-NonBlocking -Times 0 -Exactly
+    }
+
+    It 'falls back to the PowerShell writer when reg import fails' {
+        Mock Invoke-NonBlocking { [PSCustomObject]@{ Output = @('denied'); ExitCode = 5; Error = 'access denied' } }
+
+        Import-RegistryFile -message 'Apply' -path 'feature.reg'
+
+        Should -Invoke Invoke-RegistryOperationsFromRegFile -Times 1 -Exactly
+        Should -Invoke Write-Warning -Times 1 -Exactly -ParameterFilter { $Message -like "reg import failed*" }
+        $script:RegistryImportFailures | Should -Be 0
+    }
+
+    It 'does not invoke the fallback after a successful reg import' {
+        Import-RegistryFile -message 'Apply' -path 'feature.reg'
+        Should -Invoke Invoke-NonBlocking -Times 1 -Exactly
+        Should -Invoke Invoke-RegistryOperationsFromRegFile -Times 0 -Exactly
+        $script:RegistryImportFailures | Should -Be 0
+    }
+}

Tests/Invoke-Changes.Tests.ps1

@@ -0,0 +1,358 @@
+BeforeAll {
+    function Import-RegistryFile { param($Message, $path) }
+    function Remove-SelectedApps { param($Apps) }
+    function Disable-TelemetryScheduledTasks {}
+    function Enable-TelemetryScheduledTasks {}
+    function Generate-AppsList { @() }
+    function Get-FriendlyTargetUserName { 'current user' }
+    function EnableStoreSearchSuggestionsForAllUsers {}
+    function Set-StoreSearchSuggestionsEnabled { param($StoreAppsDatabase) }
+    function Get-StoreAppsDatabasePathForUser { param($UserName) 'store.db' }
+    function Get-UserName { 'Alice' }
+    function Disable-WindowsFeature { param($FeatureName) }
+    function New-RegistrySettingsBackup { param($ActionableKeys, $ExtraFeatures) }
+    function Invoke-SystemRestorePoint {}
+    function Enable-WindowsFeature { param($FeatureName) }
+    function Get-StartMenuBinPathForUser { param($UserName) 'start.bin' }
+    function Replace-StartMenu { param($startMenuBinFile, $startMenuTemplate) }
+    function Replace-StartMenuForAllUsers { param($startMenuTemplate) }
+    function DisableStoreSearchSuggestionsForAllUsers {}
+    function Set-StoreSearchSuggestionsDisabled { param($StoreAppsDatabase) }
+
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Invoke-Changes.ps1')
+}
+
+Describe 'Resolve-UndoRegFilePath' {
+    BeforeEach {
+        $script:RegfilesPath = $TestDrive
+        New-Item -ItemType Directory -Path (Join-Path $TestDrive 'Undo') -Force | Out-Null
+    }
+
+    It '<Case>' -ForEach @(
+        @{ Case = 'prefers an existing file in Undo'; FileName = 'feature.reg'; CreateUndoFile = $true; Expected = 'Undo\feature.reg' }
+        @{ Case = 'falls back to the original file name'; FileName = 'missing.reg'; CreateUndoFile = $false; Expected = 'missing.reg' }
+    ) {
+        if ($CreateUndoFile) {
+            '' | Set-Content -LiteralPath (Join-Path $TestDrive "Undo\$FileName")
+        }
+
+        Resolve-UndoRegFilePath -FileName $FileName | Should -Be $Expected
+    }
+}
+
+Describe 'Invoke-FeatureApply' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:Features = @{
+            RegistryFeature = [PSCustomObject]@{ ApplyText = 'Apply registry feature'; RegistryKey = 'feature.reg' }
+            DisableTelemetry = [PSCustomObject]@{ ApplyText = 'Disable telemetry'; RegistryKey = 'telemetry.reg' }
+            DisableBing = [PSCustomObject]@{ ApplyText = 'Disable Bing'; RegistryKey = 'bing.reg' }
+            DisableCopilot = [PSCustomObject]@{ ApplyText = 'Disable Copilot'; RegistryKey = 'copilot.reg' }
+            RemoveApps = [PSCustomObject]@{ ApplyText = 'Remove apps'; RegistryKey = '' }
+            RemoveGamingApps = [PSCustomObject]@{ ApplyText = 'Remove gaming'; RegistryKey = '' }
+            RemoveHPApps = [PSCustomObject]@{ ApplyText = 'Remove HP'; RegistryKey = '' }
+            DisableWidgets = [PSCustomObject]@{ ApplyText = 'Disable widgets'; RegistryKey = '' }
+            EnableWindowsSandbox = [PSCustomObject]@{ ApplyText = 'Enable Sandbox'; RegistryKey = '' }
+            EnableWindowsSubsystemForLinux = [PSCustomObject]@{ ApplyText = 'Enable WSL'; RegistryKey = '' }
+            ClearStart = [PSCustomObject]@{ ApplyText = 'Clear Start'; RegistryKey = '' }
+            ReplaceStart = [PSCustomObject]@{ ApplyText = 'Replace Start'; RegistryKey = '' }
+            ClearStartAllUsers = [PSCustomObject]@{ ApplyText = 'Clear Start all users'; RegistryKey = '' }
+            ReplaceStartAllUsers = [PSCustomObject]@{ ApplyText = 'Replace Start all users'; RegistryKey = '' }
+            DisableStoreSearchSuggestions = [PSCustomObject]@{ ApplyText = 'Disable Store suggestions'; RegistryKey = '' }
+        }
+        Mock Import-RegistryFile {}
+        Mock Remove-SelectedApps {}
+        Mock Disable-TelemetryScheduledTasks {}
+        Mock Generate-AppsList { @() }
+        Mock Get-FriendlyTargetUserName { 'current user' }
+        Mock Enable-WindowsFeature {}
+        Mock Get-StartMenuBinPathForUser { 'start.bin' }
+        Mock Get-UserName { 'Alice' }
+        Mock Replace-StartMenu {}
+        Mock Replace-StartMenuForAllUsers {}
+        Mock DisableStoreSearchSuggestionsForAllUsers {}
+        Mock Set-StoreSearchSuggestionsDisabled {}
+        Mock Get-StoreAppsDatabasePathForUser { 'store.db' }
+        Mock Get-Process { @() }
+        Mock Stop-Process {}
+        Mock Write-Host {}
+    }
+
+    It 'imports a registry-backed feature' {
+        Invoke-FeatureApply -FeatureId 'RegistryFeature'
+
+        Should -Invoke Import-RegistryFile -Times 1 -Exactly -ParameterFilter { $path -eq 'feature.reg' }
+        Should -Invoke Remove-SelectedApps -Times 0 -Exactly
+    }
+
+    It 'runs the telemetry side effect after importing its registry file' {
+        Invoke-FeatureApply -FeatureId 'DisableTelemetry'
+
+        Should -Invoke Import-RegistryFile -Times 1 -Exactly
+        Should -Invoke Disable-TelemetryScheduledTasks -Times 1 -Exactly
+    }
+
+    It 'does not call app removal when the generated selection is empty' {
+        Invoke-FeatureApply -FeatureId 'RemoveApps'
+
+        Should -Invoke Generate-AppsList -Times 1 -Exactly
+        Should -Invoke Remove-SelectedApps -Times 0 -Exactly
+    }
+
+    It 'passes a non-empty generated selection to app removal' {
+        Mock Generate-AppsList { @('One.App', 'Two.App') }
+
+        Invoke-FeatureApply -FeatureId 'RemoveApps'
+
+        Should -Invoke Remove-SelectedApps -Times 1 -Exactly -ParameterFilter { @($Apps).Count -eq 2 }
+    }
+
+    It 'runs registry-backed companion app removal for <FeatureId>' -ForEach @(
+        @{ FeatureId = 'DisableBing'; ExpectedApps = @('Microsoft.BingSearch') }
+        @{ FeatureId = 'DisableCopilot'; ExpectedApps = @('Microsoft.Copilot', 'XP9CXNGPPJ97XX') }
+    ) {
+        Invoke-FeatureApply -FeatureId $FeatureId
+        Should -Invoke Import-RegistryFile -Times 1 -Exactly
+        Should -Invoke Remove-SelectedApps -Times 1 -Exactly -ParameterFilter { @($Apps) -join ',' -eq $ExpectedApps -join ',' }
+    }
+
+    It 'uses the expected static app list for <FeatureId>' -ForEach @(
+        @{ FeatureId = 'RemoveGamingApps'; MinimumCount = 3; ExpectedApp = 'Microsoft.GamingApp' }
+        @{ FeatureId = 'RemoveHPApps'; MinimumCount = 10; ExpectedApp = 'AD2F1837.myHP' }
+        @{ FeatureId = 'DisableWidgets'; MinimumCount = 3; ExpectedApp = 'MicrosoftWindows.Client.WebExperience' }
+    ) {
+        Invoke-FeatureApply -FeatureId $FeatureId
+        Should -Invoke Remove-SelectedApps -Times 1 -Exactly -ParameterFilter { @($Apps).Count -ge $MinimumCount -and $Apps -contains $ExpectedApp }
+    }
+
+    It 'does not stop widget processes in WhatIf mode' {
+        $script:Params = @{ WhatIf = $true }
+        Invoke-FeatureApply -FeatureId 'DisableWidgets'
+        Should -Invoke Get-Process -Times 0 -Exactly
+        Should -Invoke Stop-Process -Times 0 -Exactly
+    }
+
+    It 'enables the expected optional Windows features' {
+        Invoke-FeatureApply -FeatureId 'EnableWindowsSandbox'
+        Invoke-FeatureApply -FeatureId 'EnableWindowsSubsystemForLinux'
+        Should -Invoke Enable-WindowsFeature -Times 1 -Exactly -ParameterFilter { $FeatureName -eq 'Containers-DisposableClientVM' }
+        Should -Invoke Enable-WindowsFeature -Times 1 -Exactly -ParameterFilter { $FeatureName -eq 'VirtualMachinePlatform' }
+        Should -Invoke Enable-WindowsFeature -Times 1 -Exactly -ParameterFilter { $FeatureName -eq 'Microsoft-Windows-Subsystem-Linux' }
+    }
+
+    It 'applies current-user Start layouts only when a target path resolves' {
+        $script:Params = @{ ReplaceStart = 'template.bin' }
+        Invoke-FeatureApply -FeatureId 'ClearStart'
+        Invoke-FeatureApply -FeatureId 'ReplaceStart'
+        Should -Invoke Replace-StartMenu -Times 1 -Exactly -ParameterFilter { $startMenuBinFile -eq 'start.bin' -and -not $startMenuTemplate }
+        Should -Invoke Replace-StartMenu -Times 1 -Exactly -ParameterFilter { $startMenuBinFile -eq 'start.bin' -and $startMenuTemplate -eq 'template.bin' }
+
+        Mock Get-StartMenuBinPathForUser { $null }
+        Invoke-FeatureApply -FeatureId 'ClearStart'
+        Should -Invoke Replace-StartMenu -Times 2 -Exactly
+    }
+
+    It 'applies all-user Start templates correctly' {
+        $script:Params = @{ ReplaceStartAllUsers = 'all-users.bin' }
+        Invoke-FeatureApply -FeatureId 'ClearStartAllUsers'
+        Invoke-FeatureApply -FeatureId 'ReplaceStartAllUsers'
+        Should -Invoke Replace-StartMenuForAllUsers -Times 2 -Exactly
+        Should -Invoke Replace-StartMenuForAllUsers -Times 1 -Exactly -ParameterFilter { $null -eq $startMenuTemplate }
+        Should -Invoke Replace-StartMenuForAllUsers -Times 1 -Exactly -ParameterFilter { $startMenuTemplate -eq 'all-users.bin' }
+    }
+
+    It 'applies Store-search scope to all users during Sysprep' {
+        $script:Params = @{ Sysprep = $true }
+        Invoke-FeatureApply -FeatureId 'DisableStoreSearchSuggestions'
+
+        Should -Invoke DisableStoreSearchSuggestionsForAllUsers -Times 1 -Exactly
+        Should -Invoke Set-StoreSearchSuggestionsDisabled -Times 0 -Exactly
+    }
+}
+
+Describe 'Invoke-ApplyFeatures' {
+    BeforeEach {
+        $script:CancelRequested = $false
+        $script:Features = @{
+            One = [PSCustomObject]@{ ApplyText = 'Apply one' }
+            Two = [PSCustomObject]@{ ApplyText = 'Apply two' }
+        }
+        $script:progressCalls = New-Object System.Collections.Generic.List[object]
+        $script:ApplyProgressCallback = { param($Step, $Total, $Text) $script:progressCalls.Add(@($Step, $Total, $Text)) }
+        Mock Invoke-FeatureApply {}
+    }
+
+    It 'reports progress and applies each feature in order' {
+        Invoke-ApplyFeatures -FeatureIds @('One', 'Two') -StartStep 3 -TotalSteps 5
+
+        Should -Invoke Invoke-FeatureApply -Times 2 -Exactly
+        $script:progressCalls | Should -HaveCount 2
+        $script:progressCalls[0] | Should -Be @(3, 5, 'Apply one')
+        $script:progressCalls[1] | Should -Be @(4, 5, 'Apply two')
+    }
+
+    It 'stops before processing work when cancellation was requested' {
+        $script:CancelRequested = $true
+
+        Invoke-ApplyFeatures -FeatureIds @('One', 'Two') -StartStep 1 -TotalSteps 2
+
+        Should -Invoke Invoke-FeatureApply -Times 0 -Exactly
+        $script:progressCalls | Should -HaveCount 0
+    }
+}
+
+Describe 'Invoke-UndoFeatures' {
+    BeforeEach {
+        $script:CancelRequested = $false
+        $script:ApplyProgressCallback = $null
+        $script:Features = @{
+            RegistryUndo = [PSCustomObject]@{ UndoLabel = 'Undo registry'; ApplyUndoText = 'Restoring registry'; RegistryUndoKey = 'undo.reg' }
+            CustomUndo = [PSCustomObject]@{ UndoLabel = 'Undo custom'; ApplyUndoText = ''; RegistryUndoKey = '' }
+        }
+        Mock Resolve-UndoRegFilePath { param($FileName) "Undo\$FileName" }
+        Mock Import-RegistryFile {}
+        Mock Invoke-FeatureUndo {}
+    }
+
+    It 'imports registry undo data and still invokes custom undo side effects' {
+        Invoke-UndoFeatures -FeatureIds @('RegistryUndo') -StartStep 1 -TotalSteps 1
+
+        Should -Invoke Import-RegistryFile -Times 1 -Exactly -ParameterFilter { $path -eq 'Undo\undo.reg' }
+        Should -Invoke Invoke-FeatureUndo -Times 1 -Exactly -ParameterFilter { $FeatureId -eq 'RegistryUndo' }
+    }
+
+    It 'handles unknown and custom features without attempting a registry import' {
+        Invoke-UndoFeatures -FeatureIds @('CustomUndo', 'Unknown') -StartStep 1 -TotalSteps 2
+
+        Should -Invoke Import-RegistryFile -Times 0 -Exactly
+        Should -Invoke Invoke-FeatureUndo -Times 2 -Exactly
+    }
+}
+
+Describe 'Invoke-FeatureUndo' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:Features = @{
+            EnableWindowsSandbox = [PSCustomObject]@{ ApplyUndoText = 'Disable Sandbox' }
+            EnableWindowsSubsystemForLinux = [PSCustomObject]@{ ApplyUndoText = 'Disable WSL' }
+            DisableTelemetry = [PSCustomObject]@{}
+            DisableStoreSearchSuggestions = [PSCustomObject]@{}
+        }
+        Mock EnableStoreSearchSuggestionsForAllUsers {}
+        Mock Set-StoreSearchSuggestionsEnabled {}
+        Mock Get-StoreAppsDatabasePathForUser { 'store.db' }
+        Mock Get-UserName { 'Alice' }
+        Mock Disable-WindowsFeature {}
+        Mock Enable-TelemetryScheduledTasks {}
+        Mock Write-Host {}
+    }
+
+    It 'undoes Store search suggestions for the selected target scope' -ForEach @(
+        @{ Params = @{ Sysprep = $true }; AllUsers = 1; CurrentUser = 0 }
+        @{ Params = @{}; AllUsers = 0; CurrentUser = 1 }
+    ) {
+        $script:Params = $Params
+        Invoke-FeatureUndo -FeatureId 'DisableStoreSearchSuggestions'
+        Should -Invoke EnableStoreSearchSuggestionsForAllUsers -Times $AllUsers -Exactly
+        Should -Invoke Set-StoreSearchSuggestionsEnabled -Times $CurrentUser -Exactly -ParameterFilter { $StoreAppsDatabase -eq 'store.db' }
+    }
+
+    It 'disables both WSL optional features in dependency-safe order' {
+        $script:disabledFeatures = [System.Collections.Generic.List[string]]::new()
+        Mock Disable-WindowsFeature { param($FeatureName) $script:disabledFeatures.Add($FeatureName) }
+        Invoke-FeatureUndo -FeatureId 'EnableWindowsSubsystemForLinux'
+        $script:disabledFeatures | Should -Be @('Microsoft-Windows-Subsystem-Linux', 'VirtualMachinePlatform')
+    }
+
+    It 'disables Sandbox and re-enables telemetry tasks' {
+        Invoke-FeatureUndo -FeatureId 'EnableWindowsSandbox'
+        Invoke-FeatureUndo -FeatureId 'DisableTelemetry'
+        Should -Invoke Disable-WindowsFeature -Times 1 -Exactly -ParameterFilter { $FeatureName -eq 'Containers-DisposableClientVM' }
+        Should -Invoke Enable-TelemetryScheduledTasks -Times 1 -Exactly
+    }
+}
+
+Describe 'Invoke-AllChanges' {
+    BeforeEach {
+        $script:Params = @{ RegistryApply = $true; CustomApply = $true }
+        $script:UndoParams = @{ RegistryUndo = $true }
+        $script:ControlParams = @('WhatIf', 'Silent', 'User', 'Sysprep')
+        $script:Features = @{
+            RegistryApply = [PSCustomObject]@{ RegistryKey = 'apply.reg' }
+            CustomApply = [PSCustomObject]@{ RegistryKey = '' }
+            RegistryUndo = [PSCustomObject]@{ RegistryUndoKey = 'undo.reg' }
+        }
+        $script:CancelRequested = $false
+        $script:ApplyProgressCallback = $null
+        Mock Test-RunningAsSystem { $false }
+        Mock Resolve-UndoRegFilePath { param($FileName) "Undo\$FileName" }
+        Mock New-RegistrySettingsBackup {}
+        Mock Invoke-SystemRestorePoint {}
+        Mock Invoke-ApplyFeatures {}
+        Mock Invoke-UndoFeatures {}
+        Mock Write-Host {}
+    }
+
+    It 'backs up registry work before applying and undoing selected features' {
+        $script:order = [System.Collections.Generic.List[string]]::new()
+        Mock New-RegistrySettingsBackup { $script:order.Add('backup') }
+        Mock Invoke-ApplyFeatures { $script:order.Add('apply') }
+        Mock Invoke-UndoFeatures { $script:order.Add('undo') }
+
+        Invoke-AllChanges
+
+        $script:order | Should -Be @('backup', 'apply', 'undo')
+        Should -Invoke New-RegistrySettingsBackup -Times 1 -Exactly -ParameterFilter {
+            $ActionableKeys -contains 'RegistryApply' -and @($ExtraFeatures).Count -eq 1 -and $ExtraFeatures[0].RegistryKey -eq 'Undo\undo.reg'
+        }
+    }
+
+    It 'prevents every mutation when registry backup creation fails' {
+        Mock New-RegistrySettingsBackup { throw 'disk full' }
+        { Invoke-AllChanges } | Should -Throw 'Registry backup failed before applying changes.*disk full'
+        Should -Invoke Invoke-ApplyFeatures -Times 0 -Exactly
+        Should -Invoke Invoke-UndoFeatures -Times 0 -Exactly
+        Should -Invoke Invoke-SystemRestorePoint -Times 0 -Exactly
+    }
+
+    It 'does not run when cancellation was already requested' {
+        $script:CancelRequested = $true
+        Invoke-AllChanges
+        Should -Invoke New-RegistrySettingsBackup -Times 0 -Exactly
+        Should -Invoke Invoke-ApplyFeatures -Times 0 -Exactly
+        Should -Invoke Invoke-UndoFeatures -Times 0 -Exactly
+    }
+
+    It 'does not enter the undo phase when cancellation occurs during apply' {
+        Mock Invoke-ApplyFeatures { $script:CancelRequested = $true }
+        Invoke-AllChanges
+        Should -Invoke Invoke-ApplyFeatures -Times 1 -Exactly
+        Should -Invoke Invoke-UndoFeatures -Times 0 -Exactly
+    }
+
+    It 'rejects SYSTEM execution without an explicit user target' {
+        Mock Test-RunningAsSystem { $true }
+        { Invoke-AllChanges } | Should -Throw "Win11Debloat is running as the SYSTEM account*"
+        Should -Invoke New-RegistrySettingsBackup -Times 0 -Exactly
+    }
+
+    It 'allows SYSTEM execution with an explicit target and filters control parameters from features' {
+        Mock Test-RunningAsSystem { $true }
+        $script:Params = @{ User = 'Alice'; WhatIf = $true; CustomApply = $true }
+        Invoke-AllChanges
+        Should -Invoke New-RegistrySettingsBackup -Times 0 -Exactly
+        Should -Invoke Invoke-ApplyFeatures -Times 1 -Exactly -ParameterFilter {
+            @($FeatureIds).Count -eq 1 -and $FeatureIds[0] -eq 'CustomApply'
+        }
+    }
+
+    It 'sequences an optional restore point before feature application' {
+        $script:Params = @{ CreateRestorePoint = $true; CustomApply = $true }
+        $script:UndoParams = @{}
+        $script:order = [System.Collections.Generic.List[string]]::new()
+        Mock Invoke-SystemRestorePoint { $script:order.Add('restore-point') }
+        Mock Invoke-ApplyFeatures { $script:order.Add('apply') }
+        Invoke-AllChanges
+        $script:order | Should -Be @('restore-point', 'apply')
+    }
+}

Tests/MainWindow-AppSelection.Tests.ps1

@@ -0,0 +1,156 @@
+BeforeAll {
+    Add-Type -AssemblyName PresentationFramework
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\MainWindow-AppSelection.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\MainWindow-Deployment.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\MainWindow-Navigation.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\MainWindow-TweaksBuilder.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\Set-WindowThemeResources.ps1')
+
+    function New-TestWindow {
+        $window = New-Object System.Windows.Window
+        [System.Windows.NameScope]::SetNameScope($window, [System.Windows.NameScope]::new())
+        $window.Resources['ProgressActiveColor'] = [System.Windows.Media.Brushes]::Green
+        $window.Resources['ProgressInactiveColor'] = [System.Windows.Media.Brushes]::Gray
+        return $window
+    }
+}
+
+Describe 'ConvertTo-NormalizedCheckboxState' {
+    It 'normalizes indeterminate tri-state checkboxes to checked' {
+        $checkBox = New-Object System.Windows.Controls.CheckBox
+        $checkBox.IsThreeState = $true
+        $checkBox.IsChecked = $null
+        Add-Member -InputObject $checkBox -MemberType NoteProperty -Name 'WasIndeterminateBeforeClick' -Value $true
+
+        ConvertTo-NormalizedCheckboxState -CheckBox $checkBox | Should -BeTrue
+        $checkBox.IsChecked | Should -BeTrue
+        $checkBox.WasIndeterminateBeforeClick | Should -BeFalse
+    }
+
+    It 'sets tri-state preset checkboxes for empty, partial, and complete selections' {
+        $checkBox = New-Object System.Windows.Controls.CheckBox
+        $checkBox.IsThreeState = $true
+
+        Set-TriStatePresetCheckBoxState -CheckBox $checkBox -Total 0 -Selected 0
+        $checkBox.IsEnabled | Should -BeFalse
+        Set-TriStatePresetCheckBoxState -CheckBox $checkBox -Total 3 -Selected 1
+        $checkBox.IsChecked.HasValue | Should -BeFalse
+        Set-TriStatePresetCheckBoxState -CheckBox $checkBox -Total 3 -Selected 3
+        $checkBox.IsChecked | Should -BeTrue
+    }
+
+    It 'rebuilds highlighted-search indexes and sorts app controls' {
+        $panel = New-Object System.Windows.Controls.StackPanel
+        $first = New-Object System.Windows.Controls.CheckBox
+        $first.Content = 'Zeta'
+        $first | Add-Member NoteProperty AppName 'Zeta'
+        $first | Add-Member NoteProperty AppDescription 'Last'
+        $first | Add-Member NoteProperty AppIdDisplay 'Zeta.App'
+        $first.Background = [System.Windows.Media.Brushes]::Yellow
+        $second = New-Object System.Windows.Controls.CheckBox
+        $second.Content = 'Alpha'
+        $second | Add-Member NoteProperty AppName 'Alpha'
+        $second | Add-Member NoteProperty AppDescription 'First'
+        $second | Add-Member NoteProperty AppIdDisplay 'Alpha.App'
+        $second.Background = [System.Windows.Media.Brushes]::Yellow
+        $null = $panel.Children.Add($first)
+        $null = $panel.Children.Add($second)
+        $script:AppSearchMatches = @()
+        $script:AppSearchMatchIndex = -1
+        $script:SortColumn = 'Name'
+        $script:SortAscending = $true
+        $nameArrow = New-Object System.Windows.Controls.TextBlock
+        $descriptionArrow = New-Object System.Windows.Controls.TextBlock
+        $appIdArrow = New-Object System.Windows.Controls.TextBlock
+        $nameArrow.RenderTransform = New-Object System.Windows.Media.RotateTransform
+        $descriptionArrow.RenderTransform = New-Object System.Windows.Media.RotateTransform
+        $appIdArrow.RenderTransform = New-Object System.Windows.Media.RotateTransform
+
+        Update-AppsPanelRebuildSearchIndex -AppsPanel $panel -ActiveMatch $second
+        Update-AppsPanelSort -AppsPanel $panel -SortArrowName $nameArrow -SortArrowDescription $descriptionArrow -SortArrowAppId $appIdArrow
+
+        $panel.Children[0].AppName | Should -Be 'Alpha'
+        $script:AppSearchMatches.Count | Should -Be 2
+        $script:AppSearchMatches[$script:AppSearchMatchIndex] | Should -Be $second
+        $nameArrow.Opacity | Should -Be 1
+    }
+
+    It 'finds matching combo-box content case-insensitively' {
+        $comboBox = New-Object System.Windows.Controls.ComboBox
+        $null = $comboBox.Items.Add('Disable telemetry')
+        $null = $comboBox.Items.Add((New-Object System.Windows.Controls.ComboBoxItem -Property @{ Content = 'Enable widgets' }))
+
+        Test-ComboBoxContainsMatch -ComboBox $comboBox -SearchText 'telemetry' | Should -BeTrue
+        Test-ComboBoxContainsMatch -ComboBox $comboBox -SearchText 'missing' | Should -BeFalse
+    }
+}
+
+Describe 'Get-PendingTweakActions' {
+    BeforeEach {
+        $script:FeatureLabelLookup = @{ DisableTelemetry = 'Disable telemetry'; EnableWidgets = 'Enable widgets' }
+        $script:UndoFeatureLabelLookup = @{ DisableTelemetry = 'Enable telemetry' }
+    }
+
+    It 'builds pending apply and undo actions from mapped checkbox state' {
+        $window = New-TestWindow
+        $applyCheckBox = New-Object System.Windows.Controls.CheckBox
+        $applyCheckBox.IsChecked = $true
+        $applyCheckBox | Add-Member NoteProperty InitialState $false
+        $undoCheckBox = New-Object System.Windows.Controls.CheckBox
+        $undoCheckBox.IsChecked = $false
+        $undoCheckBox | Add-Member NoteProperty InitialState $true
+        $window.RegisterName('ApplyTelemetry', $applyCheckBox)
+        $window.RegisterName('UndoTelemetry', $undoCheckBox)
+        $script:UiControlMappings = @{
+            ApplyTelemetry = [PSCustomObject]@{ Type = 'feature'; FeatureId = 'DisableTelemetry' }
+            UndoTelemetry = [PSCustomObject]@{ Type = 'feature'; FeatureId = 'DisableTelemetry' }
+        }
+
+        $actions = @(Get-PendingTweakActions -Window $window -ShowAppliedTweaksMode:$false | Sort-Object Action)
+
+        $actions.Action | Should -Be @('Apply', 'Undo')
+        $actions.Label | Should -Be @('Disable telemetry', 'Enable telemetry')
+    }
+
+    It 'builds a category preset map for visible mapped controls' {
+        $window = New-TestWindow
+        $checkBox = New-Object System.Windows.Controls.CheckBox
+        $checkBox.Visibility = 'Visible'
+        $window.RegisterName('DisableTelemetryCheckBox', $checkBox)
+        $script:UiControlMappings = @{ DisableTelemetryCheckBox = [PSCustomObject]@{ Category = 'Privacy'; Type = 'feature'; FeatureId = 'DisableTelemetry' } }
+
+        $map = Get-CategoryTweakPresetMap -Window $window -Category 'Privacy'
+
+        $map['DisableTelemetryCheckBox'].ControlType | Should -Be 'CheckBox'
+        $map['DisableTelemetryCheckBox'].DesiredValue | Should -BeTrue
+    }
+
+    It 'updates navigation visibility and progress indicators for an interior tab' {
+        $window = New-TestWindow
+        $tabControl = New-Object System.Windows.Controls.TabControl
+        0..3 | ForEach-Object { $null = $tabControl.Items.Add((New-Object System.Windows.Controls.TabItem)) }
+        $tabControl.SelectedIndex = 2
+        foreach ($name in @('PreviousBtn', 'NextBtn', 'BottomNavGrid')) { $window.RegisterName($name, (New-Object System.Windows.Controls.Border)) }
+        foreach ($name in @('ProgressIndicator1', 'ProgressIndicator2', 'ProgressIndicator3')) { $window.RegisterName($name, (New-Object System.Windows.Shapes.Rectangle)) }
+
+        Update-NavigationButtons -Window $window -TabControl $tabControl
+
+        $window.FindName('PreviousBtn').Visibility | Should -Be 'Visible'
+        $window.FindName('NextBtn').Visibility | Should -Be 'Visible'
+        $window.FindName('ProgressIndicator1').Fill | Should -Be $window.Resources['ProgressActiveColor']
+        $window.FindName('ProgressIndicator3').Fill | Should -Be $window.Resources['ProgressInactiveColor']
+    }
+}
+
+Describe 'Set-WindowThemeResources' {
+    It 'populates themed resources and selects the Windows 11 icon font' {
+        $window = New-TestWindow
+        $script:SharedStylesSchema = $null
+        Mock Get-ItemPropertyValue { 22631 }
+
+        Set-WindowThemeResources -window $window -usesDarkMode:$true
+
+        $window.Resources['AppBgColor'] | Should -Not -BeNullOrEmpty
+        $window.Resources['AppIconFontFamily'].Source | Should -Be 'Segoe Fluent Icons'
+    }
+}

Tests/MainWindow-Deployment.Tests.ps1

@@ -0,0 +1,33 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\MainWindow-Deployment.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\Get-SystemUsesDarkMode.ps1')
+}
+
+Describe 'Get-UndoFeatureLabel' {
+    BeforeEach {
+        $script:UndoFeatureLabelLookup = @{ DisableTelemetry = 'Enable telemetry' }
+        $script:FeatureLabelLookup = @{ DisableTelemetry = 'Disable telemetry'; DisableWidgets = 'Disable widgets' }
+    }
+
+    It 'prefers undo labels and falls back to feature labels' {
+        Get-UndoFeatureLabel -FeatureId 'DisableTelemetry' | Should -Be 'Enable telemetry'
+        Get-UndoFeatureLabel -FeatureId 'DisableWidgets' | Should -Be 'Disable widgets'
+    }
+
+    It 'reads selected app IDs from string or array settings and removes blanks' {
+        $stringSettings = [PSCustomObject]@{ Settings = @([PSCustomObject]@{ Name = 'Apps'; Value = ' One.App, ,Two.App ' }) }
+        $arraySettings = [PSCustomObject]@{ Settings = @([PSCustomObject]@{ Name = 'Apps'; Value = @(' One.App ', '', 'Two.App') }) }
+
+        Get-SavedAppIdsFromSettingsJson -SettingsJson $stringSettings | Should -Be @('One.App', 'Two.App')
+        Get-SavedAppIdsFromSettingsJson -SettingsJson $arraySettings | Should -Be @('One.App', 'Two.App')
+        Get-SavedAppIdsFromSettingsJson -SettingsJson ([PSCustomObject]@{ Settings = @() }) | Should -BeNullOrEmpty
+    }
+
+    It 'returns the AppsUseLightTheme registry preference and fails closed' {
+        Mock Get-ItemProperty { [PSCustomObject]@{ AppsUseLightTheme = 0 } }
+        Get-SystemUsesDarkMode | Should -BeTrue
+
+        Mock Get-ItemProperty { throw 'Registry unavailable' }
+        Get-SystemUsesDarkMode | Should -BeFalse
+    }
+}

Tests/Registry-BackupCreation.Tests.ps1

@@ -0,0 +1,245 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Registry-PathHelpers.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-RegFileOperations.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\User-HiveHelpers.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Invoke-Changes.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Backup-RegistryFeatureSelection.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Save-ToFile.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Backup-RegistryState.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Backup-RegistrySnapshotCapture.ps1')
+}
+
+Describe 'Get-SelectedFeatures' {
+    BeforeEach {
+        $script:Features = @{
+            First = [PSCustomObject]@{ FeatureId = 'One'; RegistryKey = 'one.reg' }
+            Duplicate = [PSCustomObject]@{ FeatureId = 'one'; RegistryKey = 'duplicate.reg' }
+            Empty = $null
+        }
+    }
+
+    It 'keeps the first matching feature and ignores unknown, null, and duplicate keys' {
+        $result = @(Get-SelectedFeatures -ActionableKeys @('missing', 'First', 'Duplicate', 'Empty'))
+
+        $result | Should -HaveCount 1
+        $result[0].RegistryKey | Should -Be 'one.reg'
+    }
+}
+
+Describe 'Get-RegistryBackupPayload' {
+    BeforeAll {
+        $script:OriginalComputerName = $env:COMPUTERNAME
+    }
+
+    BeforeEach {
+        Mock Get-RegistryBackedFeatures { param($Features) @($Features | Where-Object RegistryKey) }
+        Mock Get-RegistryBackupCapturePlans { @([PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\Example' }) }
+        Mock Get-RegistrySnapshotsForBackup { @([PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\Example'; Exists = $true }) }
+        Mock Get-RegistryBackupTargetDescription { 'CurrentUser:Tester' }
+        $env:COMPUTERNAME = 'TestComputer'
+    }
+
+    AfterAll {
+        $env:COMPUTERNAME = $script:OriginalComputerName
+    }
+
+    It 'builds a versioned payload and preserves distinct apply and undo IDs' {
+        $apply = @([PSCustomObject]@{ FeatureId = 'One'; RegistryKey = 'one.reg' }, [PSCustomObject]@{ FeatureId = 'one'; RegistryKey = 'other.reg' })
+        $undo = @([PSCustomObject]@{ FeatureId = 'UndoOne'; RegistryUndoKey = 'undo.reg' })
+
+        $result = Get-RegistryBackupPayload -SelectedFeatures $apply -UndoFeatures $undo -CreatedAt ([datetime]'2026-01-02T03:04:05Z')
+
+        $result.Version | Should -Be '1.0'
+        $result.BackupType | Should -Be 'RegistryState'
+        $result.Target | Should -Be 'CurrentUser:Tester'
+        $result.SelectedFeatures | Should -Be 'One'
+        $result.SelectedUndoFeatures | Should -Be 'UndoOne'
+        $result.RegistryKeys | Should -HaveCount 1
+    }
+
+    It 'does not add SelectedUndoFeatures when no undo features were supplied' {
+        $result = Get-RegistryBackupPayload -SelectedFeatures @() -UndoFeatures @() -CreatedAt (Get-Date)
+
+        $result.ContainsKey('SelectedUndoFeatures') | Should -BeFalse
+    }
+}
+
+Describe 'New-RegistrySettingsBackup' {
+    BeforeEach {
+        $script:RegistryBackupsPath = Join-Path $TestDrive 'Backups'
+        $script:Features = @{ Feature = [PSCustomObject]@{ FeatureId = 'Feature'; RegistryKey = 'feature.reg' } }
+        Mock Get-RegistryBackupPayload { @{ Version = '1.0' } }
+        Mock Save-ToFile { $true }
+        Mock Write-Host {}
+    }
+
+    It 'returns null and does not write when no selected feature has registry data' {
+        $script:Features.Feature.RegistryKey = ''
+
+        New-RegistrySettingsBackup -ActionableKeys @('Feature') | Should -BeNullOrEmpty
+        Should -Invoke Save-ToFile -Times 0 -Exactly
+    }
+
+    It 'creates the backup directory and saves a generated payload' {
+        $result = New-RegistrySettingsBackup -ActionableKeys @('Feature')
+
+        $result | Should -Match 'Win11Debloat-RegistryBackup-\d{8}_\d{6}\.json$'
+        Test-Path -LiteralPath $script:RegistryBackupsPath | Should -BeTrue
+        Should -Invoke Save-ToFile -Times 1 -Exactly -ParameterFilter { $FilePath -eq $result -and $MaxDepth -eq 25 }
+    }
+
+    It 'throws when persistence reports failure' {
+        Mock Save-ToFile { $false }
+
+        { New-RegistrySettingsBackup -ActionableKeys @('Feature') } | Should -Throw 'Failed to save registry backup to *'
+    }
+}
+
+Describe 'Add-RegistryPlanOperation' {
+    It 'merges duplicate value operations and upgrades a key deletion to a recursive capture' {
+        $plans = @{}
+        Add-RegistryPlanOperation -PlanMap $plans -Operation ([PSCustomObject]@{ KeyPath = 'HKEY_CURRENT_USER\Software\Example'; OperationType = 'SetValue'; ValueName = 'One' })
+        Add-RegistryPlanOperation -PlanMap $plans -Operation ([PSCustomObject]@{ KeyPath = 'HKEY_CURRENT_USER\Software\Example'; OperationType = 'DeleteValue'; ValueName = 'one' })
+        Add-RegistryPlanOperation -PlanMap $plans -Operation ([PSCustomObject]@{ KeyPath = 'HKEY_CURRENT_USER\Software\Example'; OperationType = 'DeleteKey'; ValueName = $null })
+
+        $plan = $plans['hkey_current_user\software\example']
+        $plan.IncludeSubKeys | Should -BeTrue
+        $plan.CaptureAllValues | Should -BeTrue
+        $plan.ValueNames | Should -HaveCount 1
+    }
+
+    It '<Case>' -ForEach @(
+        @{ Case = 'uses an explicit undo key'; RegistryUndoKey = 'undo.reg'; RegistryKey = 'apply.reg'; Expected = 'Undo/undo.reg' }
+        @{ Case = 'falls back to a relative regular registry key'; RegistryUndoKey = ''; RegistryKey = 'apply.reg'; Expected = 'apply.reg' }
+        @{ Case = 'preserves a rooted regular registry key'; RegistryUndoKey = ''; RegistryKey = 'C:\temp\apply.reg'; Expected = 'C:\temp\apply.reg' }
+    ) {
+        $script:RegfilesPath = $TestDrive
+        function Resolve-UndoRegFilePath { param($FileName) "Undo/$FileName" }
+
+        $expectedPath = if ([System.IO.Path]::IsPathRooted($Expected)) { $Expected } else { Join-Path $TestDrive $Expected }
+        Resolve-RegistryBackupUndoFilePath -Feature ([PSCustomObject]@{ RegistryUndoKey = $RegistryUndoKey; RegistryKey = $RegistryKey }) |
+            Should -Be $expectedPath
+    }
+}
+
+Describe 'Get-RegistryBackupCapturePlans' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:RegfilesPath = $TestDrive
+        $script:applyPath = Join-Path $TestDrive 'apply.reg'
+        $script:undoPath = Join-Path $TestDrive 'undo.reg'
+        '' | Set-Content -LiteralPath $script:applyPath
+        '' | Set-Content -LiteralPath $script:undoPath
+        Mock Get-RegistryFilePathForFeature { $script:applyPath }
+        Mock Resolve-RegistryBackupUndoFilePath { $script:undoPath }
+        Mock Get-RegFileOperations {
+            param($regFilePath)
+            if ($regFilePath -eq $script:applyPath) {
+                @(
+                    [PSCustomObject]@{ KeyPath = 'HKEY_CURRENT_USER\Software\Example'; OperationType = 'SetValue'; ValueName = 'Enabled' }
+                    [PSCustomObject]@{ KeyPath = $null; OperationType = 'SetValue'; ValueName = 'Ignored' }
+                )
+            }
+            else {
+                @([PSCustomObject]@{ KeyPath = 'hkey_current_user\software\example'; OperationType = 'DeleteValue'; ValueName = 'Removed' })
+            }
+        }
+    }
+
+    It 'merges apply and undo operations for the same path and ignores operations without a path' {
+        $plans = @(Get-RegistryBackupCapturePlans `
+            -SelectedRegistryFeatures @([PSCustomObject]@{ RegistryKey = 'apply.reg' }) `
+            -UndoRegistryFeatures @([PSCustomObject]@{ RegistryUndoKey = 'undo.reg' }))
+
+        $plans | Should -HaveCount 1
+        $plans[0].ValueNames | Should -Contain 'Enabled'
+        $plans[0].ValueNames | Should -Contain 'Removed'
+        $plans[0].ValueNames | Should -Not -Contain 'Ignored'
+    }
+
+    It 'passes Sysprep selection through to registry-file resolution' {
+        Get-RegistryBackupCapturePlans -SelectedRegistryFeatures @([PSCustomObject]@{ RegistryKey = 'apply.reg' }) -UseSysprepRegFiles | Out-Null
+
+        Should -Invoke Get-RegistryFilePathForFeature -Times 1 -Exactly -ParameterFilter { $UseSysprepRegFiles }
+    }
+
+    It 'throws a descriptive error when an apply registry file is missing' {
+        Mock Get-RegistryFilePathForFeature { Join-Path $TestDrive 'missing.reg' }
+
+        { Get-RegistryBackupCapturePlans -SelectedRegistryFeatures @([PSCustomObject]@{ RegistryKey = 'missing.reg' }) } |
+            Should -Throw 'Unable to find registry file for backup: missing.reg*'
+        Should -Invoke Get-RegFileOperations -Times 0 -Exactly
+    }
+
+    It 'throws a descriptive error when an undo registry file is missing' {
+        Mock Resolve-RegistryBackupUndoFilePath { Join-Path $TestDrive 'missing-undo.reg' }
+
+        { Get-RegistryBackupCapturePlans -UndoRegistryFeatures @([PSCustomObject]@{ RegistryUndoKey = 'missing-undo.reg' }) } |
+            Should -Throw 'Unable to find registry undo file for backup: missing-undo.reg*'
+    }
+
+    It 'skips undo features that do not resolve to a registry file' {
+        Mock Resolve-RegistryBackupUndoFilePath { $null }
+
+        @(Get-RegistryBackupCapturePlans -UndoRegistryFeatures @([PSCustomObject]@{ RegistryUndoKey = ''; RegistryKey = '' })) |
+            Should -HaveCount 0
+        Should -Invoke Get-RegFileOperations -Times 0 -Exactly
+    }
+}
+
+Describe 'Get-RegistrySnapshotsForBackup' {
+    BeforeEach {
+        $script:Params = @{}
+        Mock Get-RegistryKeySnapshot {
+            param($KeyPath)
+            [PSCustomObject]@{ Path = $KeyPath; Exists = $true }
+        }
+        Mock Invoke-WithLoadedBackupHive {
+            param($ScriptBlock, $ArgumentObject)
+            & $ScriptBlock $ArgumentObject
+        }
+    }
+
+    It 'returns an empty collection without touching the registry when there are no plans' {
+        @(Get-RegistrySnapshotsForBackup -CapturePlans @()) | Should -HaveCount 0
+        Should -Invoke Get-RegistryKeySnapshot -Times 0 -Exactly
+        Should -Invoke Invoke-WithLoadedBackupHive -Times 0 -Exactly
+    }
+
+    It 'captures each plan directly for the current user' {
+        $plans = @(
+            [PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\One'; CaptureAllValues = $true; ValueNames = @(); IncludeSubKeys = $true }
+            [PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\Two'; CaptureAllValues = $false; ValueNames = @('Value'); IncludeSubKeys = $false }
+        )
+
+        @(Get-RegistrySnapshotsForBackup -CapturePlans $plans) | Should -HaveCount 2
+        Should -Invoke Get-RegistryKeySnapshot -Times 2 -Exactly
+        Should -Invoke Invoke-WithLoadedBackupHive -Times 0 -Exactly
+    }
+
+    It 'captures through the loaded-hive wrapper in <Case>' -ForEach @(
+        @{ Case = 'User mode'; Params = @{ User = 'Alice' } }
+        @{ Case = 'Sysprep mode'; Params = @{ Sysprep = $true } }
+    ) {
+        $script:Params = $Params
+        $plan = [PSCustomObject]@{ Path = 'HKEY_USERS\Default\Software\Example'; CaptureAllValues = $false; ValueNames = @('Value'); IncludeSubKeys = $false }
+
+        @(Get-RegistrySnapshotsForBackup -CapturePlans @($plan)) | Should -HaveCount 1
+        Should -Invoke Invoke-WithLoadedBackupHive -Times 1 -Exactly
+        Should -Invoke Get-RegistryKeySnapshot -Times 1 -Exactly
+    }
+}
+
+Describe 'Invoke-WithLoadedBackupHive' {
+    BeforeEach {
+        Mock Invoke-WithTargetUserHive { param($TargetUserName) $TargetUserName }
+    }
+
+    It 'targets <ExpectedUser> in <Case>' -ForEach @(
+        @{ Case = 'Sysprep mode'; Params = @{ Sysprep = $true }; ExpectedUser = 'Default' }
+        @{ Case = 'User mode'; Params = @{ User = 'Alice' }; ExpectedUser = 'Alice' }
+    ) {
+        $script:Params = $Params
+        Invoke-WithLoadedBackupHive -ScriptBlock { } | Should -Be $ExpectedUser
+    }
+}

Tests/Registry-BackupValidation.Tests.ps1

@@ -0,0 +1,301 @@
+BeforeAll {
+    $registryPathHelperScriptPath = Join-Path $PSScriptRoot '..\Scripts\Helpers\Registry-PathHelpers.ps1'
+    $validationScriptPath = Join-Path $PSScriptRoot '..\Scripts\Features\Registry-BackupValidation.ps1'
+
+    . $registryPathHelperScriptPath
+    . $validationScriptPath
+}
+
+Describe 'Get-NormalizedSelectedFeatureIdsFromBackup' {
+    It 'returns distinct feature IDs without changing their first occurrence' {
+        $backup = [PSCustomObject]@{
+            SelectedFeatures = @('DisableTelemetry', 'disabletelemetry', 'DisableCopilot')
+        }
+
+        $result = Get-NormalizedSelectedFeatureIdsFromBackup -Backup $backup
+
+        $result.Errors | Should -BeNullOrEmpty
+        $result.SelectedFeatures | Should -Be @('DisableTelemetry', 'DisableCopilot')
+    }
+
+    It 'reports missing SelectedFeatures' {
+        $result = Get-NormalizedSelectedFeatureIdsFromBackup -Backup ([PSCustomObject]@{})
+
+        $result.SelectedFeatures | Should -BeNullOrEmpty
+        $result.Errors | Should -Contain 'Missing property: SelectedFeatures'
+    }
+
+    It 'reports non-string and empty feature IDs' {
+        $backup = [PSCustomObject]@{
+            SelectedFeatures = @('DisableTelemetry', '', 42, $null)
+        }
+
+        $result = Get-NormalizedSelectedFeatureIdsFromBackup -Backup $backup
+
+        $result.SelectedFeatures | Should -Be 'DisableTelemetry'
+        $result.Errors | Should -Contain 'SelectedFeatures must contain non-empty string feature IDs.'
+    }
+}
+
+Describe 'Get-NormalizedSelectedUndoFeatureIdsFromBackup' {
+    It 'allows backups created before SelectedUndoFeatures was introduced' {
+        $result = Get-NormalizedSelectedUndoFeatureIdsFromBackup -Backup ([PSCustomObject]@{})
+
+        $result.SelectedUndoFeatures | Should -BeNullOrEmpty
+        $result.Errors | Should -BeNullOrEmpty
+    }
+
+    It 'deduplicates undo feature IDs case-insensitively' {
+        $backup = [PSCustomObject]@{
+            SelectedUndoFeatures = @('EnableTelemetry', 'enabletelemetry')
+        }
+
+        $result = Get-NormalizedSelectedUndoFeatureIdsFromBackup -Backup $backup
+
+        $result.Errors | Should -BeNullOrEmpty
+        $result.SelectedUndoFeatures | Should -Be 'EnableTelemetry'
+    }
+}
+
+Describe 'Get-SelectedRegistryFeaturesForBackupValidation' {
+    BeforeEach {
+        $script:Features = @{
+            ApplyFeature = [PSCustomObject]@{ Id = 'ApplyFeature'; RegistryKey = 'ApplyFeature.reg' }
+            UndoFeature = [PSCustomObject]@{ Id = 'UndoFeature'; RegistryKey = 'UndoFeature.reg'; RegistryUndoKey = 'UndoFeature.undo.reg' }
+            FallbackUndoFeature = [PSCustomObject]@{ Id = 'FallbackUndoFeature'; RegistryKey = 'FallbackUndoFeature.reg'; RegistryUndoKey = '' }
+            CustomFeature = [PSCustomObject]@{ Id = 'CustomFeature'; RegistryKey = '' }
+        }
+    }
+
+    It 'creates a case-insensitive registry value-name set' {
+        $valueNames = ConvertTo-RegistryValueNameSet -ValueNames @('Enabled', 'enabled', 'Mode')
+
+        $valueNames.Count | Should -Be 2
+        $valueNames.Contains('ENABLED') | Should -BeTrue
+        $valueNames.Contains('mode') | Should -BeTrue
+    }
+
+    It 'selects registry-backed apply features and reports unknown IDs' {
+        $errors = New-Object System.Collections.Generic.List[string]
+
+        $result = @(Get-SelectedRegistryFeaturesForBackupValidation -SelectedFeatureIds @('ApplyFeature', 'CustomFeature', 'MissingFeature') -IsUndoFeature:$false -Errors $errors)
+
+        $result.Id | Should -Be 'ApplyFeature'
+        $errors | Should -Contain "Selected feature 'MissingFeature' was not found in the current feature catalog."
+    }
+
+    It 'uses undo registry keys and falls back to apply keys when needed' {
+        $errors = New-Object System.Collections.Generic.List[string]
+
+        $result = @(Get-SelectedRegistryFeaturesForBackupValidation -SelectedFeatureIds @('UndoFeature', 'FallbackUndoFeature') -IsUndoFeature:$true -Errors $errors)
+
+        $result.Id | Should -Be @('UndoFeature', 'FallbackUndoFeature')
+        $errors | Should -BeNullOrEmpty
+    }
+}
+
+Describe 'Test-RegistryValueKindNameSupported' {
+    It 'accepts supported registry value kind <KindName>' -ForEach @(
+        @{ KindName = 'dword' }
+        @{ KindName = 'QWord' }
+        @{ KindName = 'MultiString' }
+    ) {
+        Test-RegistryValueKindNameSupported -KindName $KindName | Should -BeTrue
+    }
+
+    It 'rejects <Case>' -ForEach @(
+        @{ Case = 'a null kind name'; KindName = $null }
+        @{ Case = 'an empty kind name'; KindName = '' }
+        @{ Case = 'the Unknown registry kind'; KindName = 'Unknown' }
+        @{ Case = 'the unsupported None registry kind'; KindName = 'None' }
+        @{ Case = 'an invalid registry kind name'; KindName = 'NotARegistryValueKind' }
+    ) {
+        Test-RegistryValueKindNameSupported -KindName $KindName | Should -BeFalse
+    }
+}
+
+Describe 'Test-RegistryValueDataMatchesKind' {
+    It 'accepts <Case>' -ForEach @(
+        @{ Case = 'the largest DWord'; Kind = 'DWord'; Data = [uint32]::MaxValue }
+        @{ Case = 'the largest QWord'; Kind = 'QWord'; Data = [uint64]::MaxValue }
+        @{ Case = 'non-empty Binary bytes'; Kind = 'Binary'; Data = @(0, 255) }
+        @{ Case = 'empty Binary bytes'; Kind = 'Binary'; Data = [byte[]]::new(0) }
+        @{ Case = 'a string array'; Kind = 'MultiString'; Data = @('one', 'two') }
+    ) {
+        Test-RegistryValueDataMatchesKind -KindName $Kind -Data $Data | Should -BeTrue
+    }
+
+    It 'rejects <Case>' -ForEach @(
+        @{ Case = 'an overflowing DWord'; Kind = 'DWord'; Data = '4294967296' }
+        @{ Case = 'a negative QWord'; Kind = 'QWord'; Data = -1 }
+        @{ Case = 'null Binary data'; Kind = 'Binary'; Data = $null }
+        @{ Case = 'an invalid binary byte'; Kind = 'Binary'; Data = @(0, 256) }
+        @{ Case = 'an object in a MultiString'; Kind = 'MultiString'; Data = @('one', [PSCustomObject]@{}) }
+    ) {
+        Test-RegistryValueDataMatchesKind -KindName $Kind -Data $Data | Should -BeFalse
+    }
+}
+
+Describe 'Get-NormalizedRegistryValueName' {
+    It 'normalizes a null value name to the default registry value' {
+        Get-NormalizedRegistryValueName -ValueName $null | Should -Be ''
+        Get-RegistryValueReferenceForError -SnapshotPath 'HKEY_CURRENT_USER\Software\Example' -ValueName '' |
+            Should -Be 'HKEY_CURRENT_USER\Software\Example\\(Default)'
+    }
+
+    It 'keeps a named registry value in the error reference' {
+        Get-RegistryValueReferenceForError -SnapshotPath 'HKEY_CURRENT_USER\Software\Example' -ValueName 'Setting' |
+            Should -Be 'HKEY_CURRENT_USER\Software\Example\\Setting'
+    }
+}
+
+Describe 'Normalize-RegistryKeySnapshot' {
+    It 'normalizes nested snapshots and supplies value defaults' {
+        $snapshot = [PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Example'
+            Exists = $true
+            Values = @(
+                [PSCustomObject]@{ Name = 'Enabled'; Kind = 'DWord'; Data = 1 }
+                [PSCustomObject]@{ Name = 'Removed'; Exists = $false }
+            )
+            SubKeys = @(
+                [PSCustomObject]@{
+                    Path = 'HKEY_CURRENT_USER\Software\Example\Child'
+                    Exists = $true
+                }
+            )
+        }
+
+        $result = Normalize-RegistryKeySnapshot -Snapshot $snapshot
+
+        $result.Path | Should -Be 'HKEY_CURRENT_USER\Software\Example'
+        $result.Exists | Should -BeTrue
+        $result.Values.Count | Should -Be 2
+        $result.Values[0].Exists | Should -BeTrue
+        $result.Values[0].Kind | Should -Be 'DWord'
+        $result.Values[1].Exists | Should -BeFalse
+        $result.Values[1].Kind | Should -BeNullOrEmpty
+        $result.Values[1].Data | Should -BeNullOrEmpty
+        $result.SubKeys[0].Path | Should -Be 'HKEY_CURRENT_USER\Software\Example\Child'
+        $result.SubKeys[0].Values | Should -BeNullOrEmpty
+    }
+
+    It 'rejects a snapshot without a registry path' {
+        { Normalize-RegistryKeySnapshot -Snapshot ([PSCustomObject]@{ Exists = $true }) } |
+            Should -Throw 'Backup validation failed: Registry key snapshot is missing Path.'
+    }
+}
+
+Describe 'Test-RegistrySnapshotAgainstAllowList' {
+    It 'normalizes path separators and hive casing' {
+        Get-NormalizedRegistryPathKey -Path 'hkey_current_user/Software/Example/' |
+            Should -Match '^HKEY_CURRENT_USER\\+Software\\Example$'
+    }
+
+    It 'matches configured value names case-insensitively' {
+        $planMap = New-RegistryBackupAllowListPlanMap -CapturePlans @(
+            [PSCustomObject]@{
+                Path = 'HKEY_CURRENT_USER\Software\Example'
+                IncludeSubKeys = $false
+                CaptureAllValues = $false
+                ValueNames = @('Enabled')
+            }
+        )
+        $planMatch = Find-RegistryAllowListPlanMatch -NormalizedPath (Get-NormalizedRegistryPathKey -Path 'HKEY_CURRENT_USER\Software\Example') -PlanMap $planMap
+
+        Test-RegistryValueAllowedByPlan -PlanMatch $planMatch -ValueName 'enabled' | Should -BeTrue
+        Test-RegistryValueAllowedByPlan -PlanMatch $planMatch -ValueName 'Unexpected' | Should -BeFalse
+    }
+
+    It 'allows configured values at an exact path' {
+        $planMap = New-RegistryBackupAllowListPlanMap -CapturePlans @(
+            [PSCustomObject]@{
+                Path = 'HKEY_CURRENT_USER\Software\Example'
+                IncludeSubKeys = $false
+                CaptureAllValues = $false
+                ValueNames = @('Enabled')
+            }
+        )
+        $errors = New-Object 'System.Collections.Generic.List[string]'
+        $snapshot = [PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Example'
+            Values = @([PSCustomObject]@{ Name = 'Enabled'; Exists = $true; Kind = 'DWord'; Data = 1 })
+            SubKeys = @()
+        }
+
+        Test-RegistrySnapshotAgainstAllowList -Snapshot $snapshot -PlanMap $planMap -Errors $errors
+
+        $errors | Should -BeNullOrEmpty
+    }
+
+    It 'rejects corrupt value data even when its path and kind are allowed' {
+        $planMap = New-RegistryBackupAllowListPlanMap -CapturePlans @(
+            [PSCustomObject]@{
+                Path = 'HKEY_CURRENT_USER\Software\Example'
+                IncludeSubKeys = $false
+                CaptureAllValues = $false
+                ValueNames = @('Bytes')
+            }
+        )
+        $errors = New-Object 'System.Collections.Generic.List[string]'
+        $snapshot = [PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Example'
+            Values = @([PSCustomObject]@{ Name = 'Bytes'; Exists = $true; Kind = 'Binary'; Data = @(1, 256) })
+            SubKeys = @()
+        }
+
+        Test-RegistrySnapshotAgainstAllowList -Snapshot $snapshot -PlanMap $planMap -Errors $errors
+
+        $errors | Should -HaveCount 1
+        $errors[0] | Should -BeLike "Backup contains invalid registry data for kind 'Binary'*"
+    }
+
+    It 'allows all values in descendants of a recursive plan' {
+        $planMap = New-RegistryBackupAllowListPlanMap -CapturePlans @(
+            [PSCustomObject]@{
+                Path = 'HKEY_CURRENT_USER\Software\Example'
+                IncludeSubKeys = $true
+                CaptureAllValues = $true
+                ValueNames = @()
+            }
+        )
+        $errors = New-Object 'System.Collections.Generic.List[string]'
+        $snapshot = [PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Example\Child'
+            Values = @([PSCustomObject]@{ Name = 'Unlisted'; Exists = $true; Kind = 'String'; Data = 'value' })
+            SubKeys = @()
+        }
+
+        Test-RegistrySnapshotAgainstAllowList -Snapshot $snapshot -PlanMap $planMap -Errors $errors
+
+        $errors | Should -BeNullOrEmpty
+    }
+
+    It 'reports unexpected paths and values' {
+        $planMap = New-RegistryBackupAllowListPlanMap -CapturePlans @(
+            [PSCustomObject]@{
+                Path = 'HKEY_CURRENT_USER\Software\Example'
+                IncludeSubKeys = $false
+                CaptureAllValues = $false
+                ValueNames = @('Enabled')
+            }
+        )
+        $errors = New-Object 'System.Collections.Generic.List[string]'
+        $unexpectedPathSnapshot = [PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Unexpected'
+            Values = @()
+            SubKeys = @()
+        }
+        $unexpectedValueSnapshot = [PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Example'
+            Values = @([PSCustomObject]@{ Name = 'Unexpected'; Exists = $true; Kind = 'String'; Data = 'value' })
+            SubKeys = @()
+        }
+
+        Test-RegistrySnapshotAgainstAllowList -Snapshot $unexpectedPathSnapshot -PlanMap $planMap -Errors $errors
+        Test-RegistrySnapshotAgainstAllowList -Snapshot $unexpectedValueSnapshot -PlanMap $planMap -Errors $errors
+
+        $errors | Should -Contain "Backup contains unexpected registry path 'HKEY_CURRENT_USER\Software\Unexpected' that is not allowed by SelectedFeatures."
+        $errors | Should -Contain "Backup contains unexpected value 'Unexpected' under 'HKEY_CURRENT_USER\Software\Example'."
+    }
+}

Tests/Registry-PathHelpers.Tests.ps1

@@ -0,0 +1,72 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Registry-PathHelpers.ps1')
+}
+
+Describe 'Split-RegistryPath' {
+    BeforeEach { $script:RegistryTargetHiveMountName = $null }
+
+    It 'normalizes whitespace, slashes, and a registry subkey' {
+        $result = Split-RegistryPath -path ' HKEY_CURRENT_USER/Software/Example/ '
+
+        $result.Hive | Should -Be 'HKEY_CURRENT_USER'
+        $result.SubKey | Should -Be 'Software\Example'
+    }
+
+    It 'returns null for <Case>' -ForEach @(
+        @{ Case = 'a blank path'; Path = '   ' }
+        @{ Case = 'a path without a hive'; Path = 'Software\Example' }
+        @{ Case = 'an abbreviated hive path'; Path = 'HKCU\Software\Example' }
+    ) {
+        Split-RegistryPath -path $Path | Should -BeNullOrEmpty
+    }
+
+    It 'rewrites the Default user hive only while a target hive is mounted' {
+        $script:RegistryTargetHiveMountName = 'S-1-5-21-123'
+
+        (Split-RegistryPath -path 'HKEY_USERS\Default\Software\Example').SubKey | Should -Be 'S-1-5-21-123\Software\Example'
+        (Split-RegistryPath -path 'HKEY_USERS\Other\Software\Example').SubKey | Should -Be 'Other\Software\Example'
+    }
+}
+
+Describe 'Get-RegistryFilePathForFeature' {
+    BeforeEach { $script:RegfilesPath = 'C:\Regfiles'; $script:Params = @{} }
+
+    It 'uses <Case>' -ForEach @(
+        @{ Case = 'the normal layout by default'; Params = @{}; UseSysprepRegFiles = $false; ExpectedRoot = 'C:\Regfiles' }
+        @{ Case = 'the Sysprep layout for an explicit switch'; Params = @{}; UseSysprepRegFiles = $true; ExpectedRoot = 'C:\Regfiles\Sysprep' }
+        @{ Case = 'the Sysprep layout for User mode'; Params = @{ User = 'Alice' }; UseSysprepRegFiles = $false; ExpectedRoot = 'C:\Regfiles\Sysprep' }
+    ) {
+        $script:Params = $Params
+        Get-RegistryFilePathForFeature -RegistryKey 'Feature.reg' -UseSysprepRegFiles:$UseSysprepRegFiles |
+            Should -Be (Join-Path $ExpectedRoot 'Feature.reg')
+    }
+}
+
+Describe 'Remove-RegistrySubKeyTreeIfExists' {
+    It 'deletes a subtree and ignores a key that disappears during deletion' {
+        $root = [PSCustomObject]@{ Calls = 0 }
+        $root | Add-Member ScriptMethod DeleteSubKeyTree { param($path, $throwOnMissing) $this.Calls++ }
+        { Remove-RegistrySubKeyTreeIfExists -RootKey $root -SubKeyPath 'Software\Example' } | Should -Not -Throw
+        $root.Calls | Should -Be 1
+
+        $root.PSObject.Members.Remove('DeleteSubKeyTree')
+        $root | Add-Member ScriptMethod DeleteSubKeyTree { throw [System.ArgumentException]::new('already gone') }
+        { Remove-RegistrySubKeyTreeIfExists -RootKey $root -SubKeyPath 'Software\Example' } | Should -Not -Throw
+    }
+
+    It 'preserves access-denied failures' -ForEach @(
+        @{ Exception = [System.UnauthorizedAccessException]::new('denied') }
+        @{ Exception = [System.Security.SecurityException]::new('blocked') }
+    ) {
+        $root = [PSCustomObject]@{ Failure = $Exception }
+        $root | Add-Member ScriptMethod DeleteSubKeyTree { throw $this.Failure }
+        { Remove-RegistrySubKeyTreeIfExists -RootKey $root -SubKeyPath 'Software\Example' } | Should -Throw
+    }
+
+    It 'preserves unexpected registry deletion failures' {
+        $root = [PSCustomObject]@{ Failure = [System.IO.IOException]::new('registry I/O failure') }
+        $root | Add-Member ScriptMethod DeleteSubKeyTree { throw $this.Failure }
+
+        { Remove-RegistrySubKeyTreeIfExists -RootKey $root -SubKeyPath 'Software\Example' } | Should -Throw '*registry I/O failure*'
+    }
+}

Tests/Registry-SnapshotApply.Tests.ps1

@@ -0,0 +1,205 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Registry-PathHelpers.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Backup-RegistrySnapshotCapture.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Restore-RegistryApplyState.ps1')
+
+    function New-FakeRegistryKey {
+        param(
+            [string]$Name = 'HKEY_CURRENT_USER\Software\Example',
+            [hashtable]$Values = @{},
+            [hashtable]$Kinds = @{},
+            [hashtable]$Children = @{}
+        )
+
+        $key = [PSCustomObject]@{
+            Name = $Name
+            Values = $Values
+            Kinds = $Kinds
+            Children = $Children
+            Closed = $false
+            DeletedValues = [System.Collections.Generic.List[string]]::new()
+            SetCalls = [System.Collections.Generic.List[object]]::new()
+        }
+        $key | Add-Member ScriptMethod GetValueNames { @($this.Kinds.Keys) }
+        $key | Add-Member ScriptMethod GetValueKind { param($valueName) $this.Kinds[$valueName] }
+        $key | Add-Member ScriptMethod GetValue { param($valueName, $defaultValue, $options) $this.Values[$valueName] }
+        $key | Add-Member ScriptMethod GetSubKeyNames { @($this.Children.Keys) }
+        $key | Add-Member ScriptMethod OpenSubKey { param($subKeyName, $writable) $this.Children[$subKeyName] }
+        $key | Add-Member ScriptMethod Close { $this.Closed = $true }
+        $key | Add-Member ScriptMethod DeleteValue { param($valueName, $throwOnMissing) $this.DeletedValues.Add([string]$valueName) }
+        $key | Add-Member ScriptMethod SetValue { param($valueName, $data, $kind) $this.SetCalls.Add(@($valueName, $data, $kind)) }
+        return $key
+    }
+}
+
+Describe 'Convert-RegistryValueToSnapshot' {
+    It 'normalizes <Case> without expanding registry strings' -ForEach @(
+        @{ Case = 'null binary'; Kind = [Microsoft.Win32.RegistryValueKind]::Binary; Data = $null; Expected = @() }
+        @{ Case = 'empty binary'; Kind = [Microsoft.Win32.RegistryValueKind]::Binary; Data = [byte[]]::new(0); Expected = @() }
+        @{ Case = 'binary'; Kind = [Microsoft.Win32.RegistryValueKind]::Binary; Data = [byte[]](1, 255); Expected = @(1, 255) }
+        @{ Case = 'multi-string'; Kind = [Microsoft.Win32.RegistryValueKind]::MultiString; Data = [string[]]@('one', 'two'); Expected = @('one', 'two') }
+        @{ Case = 'unsigned DWord'; Kind = [Microsoft.Win32.RegistryValueKind]::DWord; Data = -1; Expected = [uint32]::MaxValue }
+        @{ Case = 'unsigned QWord'; Kind = [Microsoft.Win32.RegistryValueKind]::QWord; Data = -1L; Expected = [uint64]::MaxValue }
+        @{ Case = 'expandable string'; Kind = [Microsoft.Win32.RegistryValueKind]::ExpandString; Data = '%TEMP%'; Expected = '%TEMP%' }
+    ) {
+        $key = New-FakeRegistryKey -Values @{ Value = $Data } -Kinds @{ Value = $Kind }
+        $snapshot = Convert-RegistryValueToSnapshot -RegistryKey $key -ValueName 'Value'
+        $snapshot.Exists | Should -BeTrue
+        $snapshot.Kind | Should -Be $Kind.ToString()
+        if ($Kind -eq [Microsoft.Win32.RegistryValueKind]::Binary) {
+            $snapshot.Data -is [array] | Should -BeTrue
+            $snapshot.Data.Count | Should -Be $Expected.Count
+            if ($Expected.Count -gt 0) {
+                $snapshot.Data | Should -Be $Expected
+            }
+            return
+        }
+        $snapshot.Data | Should -Be $Expected
+    }
+
+    It 'rejects REG_NONE values because their data cannot be read reliably through .NET' {
+        $key = New-FakeRegistryKey -Values @{ Value = [byte[]](1) } -Kinds @{ Value = [Microsoft.Win32.RegistryValueKind]::None }
+
+        { Convert-RegistryValueToSnapshot -RegistryKey $key -ValueName 'Value' } |
+            Should -Throw 'REG_NONE registry values are not supported for backup*'
+    }
+}
+
+Describe 'Registry value backup round trip' {
+    BeforeAll {
+        $script:RoundTripRegistrySubKey = "Software\Win11Debloat\Tests\RegistrySnapshotRoundTrip-$([guid]::NewGuid().ToString('N'))"
+        $script:RoundTripRegistryKey = [Microsoft.Win32.Registry]::CurrentUser.CreateSubKey($script:RoundTripRegistrySubKey)
+    }
+
+    AfterAll {
+        if ($script:RoundTripRegistryKey) {
+            $script:RoundTripRegistryKey.Close()
+        }
+        [Microsoft.Win32.Registry]::CurrentUser.DeleteSubKeyTree($script:RoundTripRegistrySubKey, $false)
+    }
+
+    It 'captures, serializes, and restores <Case> values' -ForEach @(
+        @{ Case = 'String'; Kind = [Microsoft.Win32.RegistryValueKind]::String; Data = 'value' }
+        @{ Case = 'ExpandString'; Kind = [Microsoft.Win32.RegistryValueKind]::ExpandString; Data = '%TEMP%\value' }
+        @{ Case = 'Binary'; Kind = [Microsoft.Win32.RegistryValueKind]::Binary; Data = [byte[]](1) }
+        @{ Case = 'DWord'; Kind = [Microsoft.Win32.RegistryValueKind]::DWord; Data = [int]42 }
+        @{ Case = 'MultiString'; Kind = [Microsoft.Win32.RegistryValueKind]::MultiString; Data = [string[]]@('one', 'two') }
+        @{ Case = 'QWord'; Kind = [Microsoft.Win32.RegistryValueKind]::QWord; Data = [int64]42 }
+    ) {
+        $sourceName = "Source-$Case"
+        $restoredName = "Restored-$Case"
+        $script:RoundTripRegistryKey.SetValue($sourceName, $Data, $Kind)
+
+        $snapshot = Convert-RegistryValueToSnapshot -RegistryKey $script:RoundTripRegistryKey -ValueName $sourceName
+        $serializedSnapshot = $snapshot | ConvertTo-Json -Depth 5 | ConvertFrom-Json
+        $serializedSnapshot.Name = $restoredName
+
+        Restore-RegistryValueSnapshot -RegistryKey $script:RoundTripRegistryKey -Snapshot $serializedSnapshot
+        $restoredSnapshot = Convert-RegistryValueToSnapshot -RegistryKey $script:RoundTripRegistryKey -ValueName $restoredName
+
+        $restoredSnapshot.Kind | Should -Be $snapshot.Kind
+        if ($Kind -in @([Microsoft.Win32.RegistryValueKind]::Binary, [Microsoft.Win32.RegistryValueKind]::None, [Microsoft.Win32.RegistryValueKind]::MultiString)) {
+            $restoredSnapshot.Data -is [array] | Should -BeTrue
+        }
+        $restoredSnapshot.Data | Should -Be $snapshot.Data
+    }
+}
+
+Describe 'Convert-RegistryKeyToSnapshot' {
+    It 'captures selected missing values and recursively closes child keys' {
+        $child = New-FakeRegistryKey -Name 'HKEY_CURRENT_USER\Software\Example\Child' -Values @{ ChildValue = 'data' } -Kinds @{ ChildValue = [Microsoft.Win32.RegistryValueKind]::String }
+        $root = New-FakeRegistryKey -Values @{ Present = 1 } -Kinds @{ Present = [Microsoft.Win32.RegistryValueKind]::DWord } -Children @{ Child = $child }
+
+        $snapshot = Convert-RegistryKeyToSnapshot -RegistryKey $root -FullPath $root.Name -ValueNames @('Missing', 'Present') -IncludeSubKeys:$true
+
+        $snapshot.Values | Should -HaveCount 2
+        ($snapshot.Values | Where-Object Name -eq 'Missing').Exists | Should -BeFalse
+        $snapshot.SubKeys | Should -HaveCount 1
+        $snapshot.SubKeys[0].Values[0].Data | Should -Be 'data'
+        $child.Closed | Should -BeTrue
+    }
+}
+
+Describe 'Get-RegistryKeySnapshot' {
+    BeforeEach {
+        Mock Split-RegistryPath { [PSCustomObject]@{ Hive = 'HKEY_CURRENT_USER'; SubKey = 'Software\Example' } }
+    }
+
+    It 'returns an explicit non-existent snapshot when the key is absent' {
+        $root = [PSCustomObject]@{}
+        $root | Add-Member ScriptMethod OpenSubKey { $null }
+        Mock Get-RegistryRootKey { $root }
+
+        $snapshot = Get-RegistryKeySnapshot -KeyPath 'HKEY_CURRENT_USER\Software\Example'
+        $snapshot.Exists | Should -BeFalse
+        $snapshot.Values | Should -HaveCount 0
+    }
+
+    It 'closes an opened root snapshot key' {
+        $key = New-FakeRegistryKey
+        $root = [PSCustomObject]@{ Key = $key }
+        $root | Add-Member ScriptMethod OpenSubKey { $this.Key }
+        Mock Get-RegistryRootKey { $root }
+
+        Get-RegistryKeySnapshot -KeyPath 'HKEY_CURRENT_USER\Software\Example' | Out-Null
+        $key.Closed | Should -BeTrue
+    }
+}
+
+Describe 'Restore-RegistryValueSnapshot' {
+    It 'deletes a missing value using the default-value name when necessary' {
+        $key = New-FakeRegistryKey
+        Restore-RegistryValueSnapshot -RegistryKey $key -Snapshot ([PSCustomObject]@{ Name = $null; Exists = $false })
+        $key.DeletedValues | Should -Be @('')
+    }
+
+    It 'sets a value with its original kind and converted bit pattern' {
+        $key = New-FakeRegistryKey
+        Restore-RegistryValueSnapshot -RegistryKey $key -Snapshot ([PSCustomObject]@{ Name = 'Large'; Exists = $true; Kind = 'QWord'; Data = [uint64]::MaxValue })
+        $key.SetCalls | Should -HaveCount 1
+        $key.SetCalls[0][0] | Should -Be 'Large'
+        $key.SetCalls[0][1] | Should -Be ([int64]-1)
+        $key.SetCalls[0][1].GetType() | Should -Be ([int64])
+        $key.SetCalls[0][2] | Should -Be ([Microsoft.Win32.RegistryValueKind]::QWord)
+    }
+
+    It 'does not silently downgrade a failed value write to Binary' {
+        $key = New-FakeRegistryKey
+        $key.PSObject.Members.Remove('SetValue')
+        $key | Add-Member ScriptMethod SetValue { throw 'write denied' }
+        { Restore-RegistryValueSnapshot -RegistryKey $key -Snapshot ([PSCustomObject]@{ Name = 'Value'; Exists = $true; Kind = 'String'; Data = 'data' }) } |
+            Should -Throw '*write denied*'
+    }
+}
+
+Describe 'Restore-RegistryKeySnapshot - mutation flow' {
+    BeforeEach {
+        Mock Split-RegistryPath {
+            param($path)
+            [PSCustomObject]@{ Hive = 'HKEY_CURRENT_USER'; SubKey = $path.Substring('HKEY_CURRENT_USER\'.Length) }
+        }
+        Mock Remove-RegistrySubKeyTreeIfExists {}
+    }
+
+    It 'removes a key that did not exist when the backup was created' {
+        Mock Get-RegistryRootKey { [PSCustomObject]@{} }
+        Restore-RegistryKeySnapshot -Snapshot ([PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\Gone'; Exists = $false; Values = @(); SubKeys = @() })
+        Should -Invoke Remove-RegistrySubKeyTreeIfExists -Times 1 -Exactly -ParameterFilter { $SubKeyPath -eq 'Software\Gone' }
+    }
+
+    It 'creates, populates, and closes an existing key snapshot' {
+        $key = New-FakeRegistryKey
+        $root = [PSCustomObject]@{ Key = $key }
+        $root | Add-Member ScriptMethod CreateSubKey { param($path) $this.Key }
+        Mock Get-RegistryRootKey { $root }
+
+        Restore-RegistryKeySnapshot -Snapshot ([PSCustomObject]@{
+            Path = 'HKEY_CURRENT_USER\Software\Example'; Exists = $true
+            Values = @([PSCustomObject]@{ Name = 'Enabled'; Exists = $true; Kind = 'DWord'; Data = 1 })
+            SubKeys = @()
+        })
+
+        $key.SetCalls | Should -HaveCount 1
+        $key.Closed | Should -BeTrue
+    }
+}

Tests/Remove-SelectedApps.Tests.ps1

@@ -0,0 +1,186 @@
+BeforeAll {
+    function Get-TargetUserForAppRemoval { 'AllUsers' }
+    function Get-WingetInstalledApps { param($TimeOut, [switch]$NonBlocking) @() }
+    function Test-AppInWingetList { param($appId, $InstalledList) $false }
+    function Invoke-NonBlocking { param($ScriptBlock, $ArgumentList) }
+    function Get-UserName { 'Alice' }
+    function Invoke-ForceRemoveEdge {}
+    function Show-MessageBox { 'No' }
+    function Invoke-WithTargetUserHive { param($TargetUserName, $ScriptBlock, $ArgumentObject) }
+    function Invoke-RegistryOperation { param($Operation, $RegFilePath) }
+
+    . (Join-Path $PSScriptRoot '..\Scripts\AppRemoval\Remove-SelectedApps.ps1')
+}
+
+Describe 'Remove-SelectedApps' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:CancelRequested = $false
+        $script:ApplySubStepCallback = $null
+        $script:WingetInstalled = $true
+        Mock Get-TargetUserForAppRemoval { 'AllUsers' }
+        Mock Get-AppRemovalMethod { 'Appx' }
+        Mock Remove-WinGetApp {}
+        Mock Remove-AppxApp {}
+        Mock Test-AppStillInstalled { $false }
+        Mock Get-WingetInstalledApps { @() }
+        Mock Request-EdgeForceRemove {}
+        Mock Write-Host {}
+    }
+
+    It 'honors WhatIf without invoking either removal backend' {
+        $script:Params = @{ WhatIf = $true }
+        Remove-SelectedApps -appsList @('One.App', 'Two.App')
+        Should -Invoke Remove-WinGetApp -Times 0 -Exactly
+        Should -Invoke Remove-AppxApp -Times 0 -Exactly
+        Should -Invoke Write-Host -Times 2 -Exactly -ParameterFilter { $Object -like '*WhatIf*Remove App*' }
+    }
+
+    It 'dispatches each app to its configured backend and target scope' {
+        Mock Get-AppRemovalMethod { param($appId) if ($appId -eq 'Winget.App') { 'WinGet' } else { 'Appx' } }
+        Remove-SelectedApps -appsList @('Winget.App', 'Appx.App')
+        Should -Invoke Remove-WinGetApp -Times 1 -Exactly -ParameterFilter { $app -eq 'Winget.App' }
+        Should -Invoke Remove-AppxApp -Times 1 -Exactly -ParameterFilter { $app -eq 'Appx.App' -and $targetUser -eq 'AllUsers' }
+    }
+
+    It 'stops before the first removal when cancellation is requested' {
+        $script:CancelRequested = $true
+        Remove-SelectedApps -appsList @('One.App')
+        Should -Invoke Remove-WinGetApp -Times 0 -Exactly
+        Should -Invoke Remove-AppxApp -Times 0 -Exactly
+    }
+
+    It 'prompts for forced Edge removal at most once after failed winget removals' {
+        Mock Get-AppRemovalMethod { 'WinGet' }
+        Mock Test-AppStillInstalled { $true }
+        Remove-SelectedApps -appsList @('Microsoft.Edge', 'XPFFTQ037JWMHS')
+        Should -Invoke Request-EdgeForceRemove -Times 1 -Exactly
+    }
+}
+
+Describe 'Get-AppRemovalMethod' {
+    BeforeEach {
+        $script:AppRemovalMethodCache = $null
+        $script:AppsListFilePath = Join-Path $TestDrive 'Apps.json'
+    }
+
+    It 'caches aliases and skips malformed IDs' {
+        '{"Apps":[{"AppId":[" One.App ","Alias.App"],"RemovalMethod":"WinGet"},{"AppId":null},{"AppId":42},{"AppId":"Two.App"}]}' |
+            Set-Content -LiteralPath $script:AppsListFilePath -Encoding UTF8
+
+        Get-AppRemovalMethod -appId 'One.App' | Should -Be 'WinGet'
+        Get-AppRemovalMethod -appId 'Alias.App' | Should -Be 'WinGet'
+        Get-AppRemovalMethod -appId 'Two.App' | Should -Be 'Appx'
+        Get-AppRemovalMethod -appId 'Unknown.App' | Should -Be 'Appx'
+    }
+
+    It 'warns and defaults to Appx when the catalog is malformed' {
+        'not json' | Set-Content -LiteralPath $script:AppsListFilePath
+        Mock Write-Warning {}
+        Get-AppRemovalMethod -appId 'Unknown.App' | Should -Be 'Appx'
+        Should -Invoke Write-Warning -Times 1 -Exactly
+    }
+}
+
+Describe 'Remove-WinGetApp' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:WingetInstalled = $true
+        Mock Invoke-NonBlocking {}
+        Mock Set-RunOnceWingetTask {}
+        Mock Get-UserName { 'Alice' }
+        Mock Write-Host {}
+    }
+
+    It 'reports unavailable winget without invoking or scheduling removal' {
+        $script:WingetInstalled = $false
+        Remove-WinGetApp -app 'One.App'
+        Should -Invoke Invoke-NonBlocking -Times 0 -Exactly
+        Should -Invoke Set-RunOnceWingetTask -Times 0 -Exactly
+    }
+
+    It 'schedules removal only for explicit user or Sysprep targets' -ForEach @(
+        @{ Params = @{}; Scheduled = 0 }
+        @{ Params = @{ User = 'Alice' }; Scheduled = 1 }
+        @{ Params = @{ Sysprep = $true }; Scheduled = 1 }
+    ) {
+        $script:Params = $Params
+        Remove-WinGetApp -app 'One.App'
+        Should -Invoke Invoke-NonBlocking -Times 1 -Exactly -ParameterFilter { $ArgumentList -eq 'One.App' }
+        Should -Invoke Set-RunOnceWingetTask -Times $Scheduled -Exactly -ParameterFilter { $appId -eq 'One.App' }
+    }
+}
+
+Describe 'Remove-AppxApp' {
+    BeforeEach { Mock Invoke-NonBlocking {} }
+
+    It 'passes the wildcard and target user data for <Target>' -ForEach @(
+        @{ Target = 'AllUsers'; ExpectedArguments = 1 }
+        @{ Target = 'CurrentUser'; ExpectedArguments = 1 }
+        @{ Target = 'Alice'; ExpectedArguments = 2 }
+    ) {
+        Remove-AppxApp -app 'One.App' -targetUser $Target
+        Should -Invoke Invoke-NonBlocking -Times 1 -Exactly -ParameterFilter {
+            @($ArgumentList).Count -eq $ExpectedArguments -and @($ArgumentList)[0] -eq '*One.App*' -and
+            ($ExpectedArguments -eq 1 -or @($ArgumentList)[1] -eq 'Alice')
+        }
+    }
+}
+
+Describe 'Test-AppStillInstalled' {
+    BeforeEach {
+        $script:WingetInstalled = $true
+        Mock Get-AppxPackage { $null }
+        Mock Test-AppInWingetList { $false }
+        Mock Get-WingetInstalledApps { @() }
+        Mock Write-Warning {}
+    }
+
+    It 'prefers all-user Appx detection and avoids winget lookup' {
+        Mock Get-AppxPackage { [PSCustomObject]@{ Name = 'One.App' } }
+        Test-AppStillInstalled -appId 'One.App' | Should -BeTrue
+        Should -Invoke Get-AppxPackage -Times 1 -Exactly -ParameterFilter { $AllUsers }
+        Should -Invoke Get-WingetInstalledApps -Times 0 -Exactly
+    }
+
+    It 'uses a supplied winget list without launching a live query' {
+        Mock Test-AppInWingetList { $true }
+        Test-AppStillInstalled -appId 'One.App' -InstalledList @([PSCustomObject]@{ Id = 'One.App' }) | Should -BeTrue
+        Should -Invoke Get-WingetInstalledApps -Times 0 -Exactly
+    }
+
+    It 'warns when a non-Appx app cannot be verified without winget' {
+        $script:WingetInstalled = $false
+        Test-AppStillInstalled -appId 'One.App' | Should -BeFalse
+        Should -Invoke Write-Warning -Times 1 -Exactly
+    }
+}
+
+Describe 'Set-RunOnceWingetTask' {
+    BeforeEach {
+        $script:Params = @{ User = 'Alice' }
+        Mock Invoke-WithTargetUserHive {
+            param($TargetUserName, $ScriptBlock, $ArgumentObject)
+            & $ScriptBlock $ArgumentObject
+        }
+        $script:runOnceOperation = $null
+        Mock Invoke-RegistryOperation {
+            param($Operation)
+            $script:runOnceOperation = $Operation
+        }
+    }
+
+    It 'encodes shell metacharacters and writes a safe RunOnce operation' {
+        Set-RunOnceWingetTask -appId "Vendor.App&'Test"
+        Should -Invoke Invoke-WithTargetUserHive -Times 1 -Exactly -ParameterFilter { $TargetUserName -eq 'Alice' }
+        Should -Invoke Invoke-RegistryOperation -Times 1 -Exactly -ParameterFilter {
+            $Operation.ValueName -eq "Uninstall_Vendor.App&'Test" -and
+            $RegFilePath -eq '<dynamic>'
+        }
+
+        $script:runOnceOperation.ValueData | Should -Match '^powershell\.exe -NoProfile -EncodedCommand [A-Za-z0-9+/=]+$'
+        $encodedCommand = $script:runOnceOperation.ValueData -replace '^powershell\.exe -NoProfile -EncodedCommand ', ''
+        $decodedCommand = [System.Text.Encoding]::Unicode.GetString([Convert]::FromBase64String($encodedCommand))
+        $decodedCommand | Should -Be "winget uninstall --accept-source-agreements --disable-interactivity --id 'Vendor.App&''Test'"
+    }
+}

Tests/Replace-StartMenu.Tests.ps1

@@ -0,0 +1,108 @@
+BeforeAll {
+    function Get-UserDirectory { param($userName, $fileName, $exitIfPathNotFound) }
+
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Replace-StartMenu.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Telemetry-ScheduledTasks.ps1')
+}
+
+Describe 'Get-StartMenuUserNameFromPath' {
+    It 'extracts a user name from a start-menu path and falls back for unknown paths' {
+        Get-StartMenuUserNameFromPath -StartMenuBinFile 'C:\Users\Alice\AppData\Local\Packages\Start\start2.bin' | Should -Be 'Alice'
+        Get-StartMenuUserNameFromPath -StartMenuBinFile 'C:\Temp\start2.bin' | Should -Be 'unknown'
+    }
+
+    It 'returns the latest current-user start-menu backup' {
+        Mock Get-ChildItem {
+            @(
+                [PSCustomObject]@{ Name = 'Win11Debloat-StartBackup-20260101_120000.bak'; FullName = 'C:\Backups\older.bak' }
+                [PSCustomObject]@{ Name = 'Win11Debloat-StartBackup-20260102_120000.bak'; FullName = 'C:\Backups\newer.bak' }
+            )
+        }
+
+        Get-StartMenuBackupPath -Scope CurrentUser | Should -Be 'C:\Backups\newer.bak'
+    }
+
+    It 'returns the first available all-users start-menu backup' {
+        $script:allUsersPath = 'C:\Users\*\AppData\Local\Packages\Start\LocalState'
+        Mock Get-UserDirectory { $script:allUsersPath }
+        Mock Get-ChildItem {
+            param($Path)
+            if ($Path -eq $script:allUsersPath) {
+                return [PSCustomObject]@{ FullName = 'C:\Users\Alice\AppData\Local\Packages\Start\LocalState' }
+            }
+
+            return [PSCustomObject]@{ Name = 'Win11Debloat-StartBackup-20260103_120000.bak'; FullName = 'C:\Users\Alice\backup.bak' }
+        }
+
+        Get-StartMenuBackupPath -Scope AllUsers | Should -Be 'C:\Users\Alice\backup.bak'
+    }
+
+    It 'restores a start menu backup and preserves the replaced file' {
+        $script:Params = @{}
+        $startMenuFile = Join-Path $TestDrive 'start2.bin'
+        $backupFile = Join-Path $TestDrive 'Win11Debloat-StartBackup-20260101_120000.bak'
+        Set-Content -LiteralPath $startMenuFile -Value 'current'
+        Set-Content -LiteralPath $backupFile -Value 'backup'
+
+        $result = Restore-StartMenuFromBackup -StartMenuBinFile $startMenuFile -BackupFilePath $backupFile
+
+        $result.Result | Should -BeTrue
+        Get-Content -LiteralPath $startMenuFile -Raw | Should -Match 'backup'
+        @(Get-ChildItem -LiteralPath $TestDrive -Filter 'Win11Debloat-StartRestore-*.bak').Count | Should -Be 1
+    }
+
+    It 'reports a missing backup without changing the start-menu file' {
+        $script:Params = @{}
+        $startMenuFile = Join-Path $TestDrive 'start2.bin'
+        Set-Content -LiteralPath $startMenuFile -Value 'current'
+
+        $result = Restore-StartMenuFromBackup -StartMenuBinFile $startMenuFile -BackupFilePath (Join-Path $TestDrive 'missing.bak')
+
+        $result.Result | Should -BeFalse
+        Get-Content -LiteralPath $startMenuFile -Raw | Should -Match 'current'
+    }
+
+    It 'delegates current-user restore to the common backup operation' {
+        $script:Params = @{}
+        Mock Restore-StartMenuFromBackup { [PSCustomObject]@{ Result = $true } }
+
+        Restore-StartMenu -BackupFilePath 'C:\Backups\backup.bak' | Should -Not -BeNullOrEmpty
+        Should -Invoke Restore-StartMenuFromBackup -Times 1 -Exactly -ParameterFilter { $BackupFilePath -eq 'C:\Backups\backup.bak' }
+    }
+
+    It 'restores every discovered user and removes the default-profile start menu' {
+        $script:Params = @{}
+        $script:allUsersStartPath = 'C:\Users\*\LocalState'
+        $script:defaultStartPath = Join-Path $TestDrive 'DefaultLocalState'
+        $defaultBin = Join-Path $script:defaultStartPath 'start2.bin'
+        New-Item -ItemType Directory -Path $script:defaultStartPath | Out-Null
+        Set-Content -LiteralPath $defaultBin -Value 'template'
+        Mock Get-UserDirectory { param($userName) if ($userName -eq '*') { $script:allUsersStartPath } else { $script:defaultStartPath } }
+        Mock Get-ChildItem { param($Path) if ($Path -eq $script:allUsersStartPath) { [PSCustomObject]@{ FullName = 'C:\Users\Alice\LocalState' } } }
+        Mock Restore-StartMenuFromBackup { [PSCustomObject]@{ UserName = 'Alice'; Result = $true; Message = 'Restored' } }
+
+        $result = @(Restore-StartMenuForAllUsers -BackupFilePath 'C:\Backups\backup.bak')
+
+        $result.Count | Should -Be 2
+        Should -Invoke Restore-StartMenuFromBackup -Times 1 -Exactly
+        Test-Path -LiteralPath $defaultBin | Should -BeFalse
+    }
+}
+
+Describe 'Get-TelemetryScheduledTasks' {
+    It 'returns the expected telemetry task catalog' {
+        $tasks = @(Get-TelemetryScheduledTasks)
+
+        $tasks.Count | Should -Be 8
+        @($tasks | ForEach-Object { "$($_.Path)|$($_.Name)" }) | Should -Be @(
+            '\Microsoft\Windows\Application Experience\|Microsoft Compatibility Appraiser'
+            '\Microsoft\Windows\Application Experience\|Microsoft Compatibility Appraiser Exp'
+            '\Microsoft\Windows\Application Experience\|ProgramDataUpdater'
+            '\Microsoft\Windows\Application Experience\|StartupAppTask'
+            '\Microsoft\Windows\Customer Experience Improvement Program\|Consolidator'
+            '\Microsoft\Windows\Customer Experience Improvement Program\|UsbCeip'
+            '\Microsoft\Windows\DiskDiagnostic\|Microsoft-Windows-DiskDiagnosticDataCollector'
+            '\Microsoft\Windows\Autochk\|Proxy'
+        )
+    }
+}

Tests/Resolve-UserProfilePath.Tests.ps1

@@ -0,0 +1,141 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Resolve-UserProfilePath.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Test-UserProfileExists.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-UserDirectory.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Test-ModernStandbySupport.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Invoke-RestartExplorer.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Threading\Invoke-DoEvents.ps1')
+
+    function powercfg { $script:PowerCfgOutput }
+    function Wait-ForKeyPress {}
+    function Get-RebootFeatureLabels { @() }
+}
+
+Describe 'Test-UserProfileExists' {
+    BeforeEach {
+        Mock Resolve-UserProfileContext {
+            [PSCustomObject]@{ ProfilePath = 'C:\Users\Alice'; UserSid = 'S-1-5-21-1000' }
+        }
+        Mock Wait-ForKeyPress {}
+        Mock Write-Error {}
+    }
+
+    It 'rejects blank and path-unsafe user names before resolving a profile' {
+        Test-UserProfileExists -userName '' | Should -BeFalse
+        Test-UserProfileExists -userName 'Alice[1]' | Should -BeFalse
+        Should -Invoke Resolve-UserProfileContext -Times 0 -Exactly
+    }
+
+    It 'accepts a resolved ordinary user and the Default profile without a SID' {
+        Test-UserProfileExists -userName ' Alice ' | Should -BeTrue
+        Mock Resolve-UserProfileContext { [PSCustomObject]@{ ProfilePath = 'C:\Users\Default'; UserSid = $null } }
+        Test-UserProfileExists -userName 'Default' | Should -BeTrue
+    }
+
+    It 'returns a resolved profile path and optionally appends a file name' {
+        Mock Test-Path { $true }
+
+        Get-UserDirectory -userName 'Alice' | Should -Be 'C:\Users\Alice'
+        Get-UserDirectory -userName 'Alice' -fileName 'AppData\Local' | Should -Be 'C:\Users\Alice\AppData\Local'
+    }
+}
+
+Describe 'Test-ModernStandbySupport' {
+    BeforeEach {
+        $script:Params = @{}
+        Mock Write-Host {}
+    }
+
+    It 'detects S0 Modern Standby from powercfg output' {
+        $script:PowerCfgOutput = @('The following sleep states are available on this system:', '    Standby (S0 Low Power Idle) Network Connected')
+
+        Test-ModernStandbySupport | Should -BeTrue
+    }
+
+    It 'does not restart Explorer for WhatIf or an explicit skip' {
+        Mock Stop-Process {}
+        $script:Params = @{ WhatIf = $true }
+        Invoke-RestartExplorer
+        $script:Params = @{ NoRestartExplorer = $true }
+        Invoke-RestartExplorer
+
+        Should -Invoke Stop-Process -Times 0 -Exactly
+    }
+
+    It 'restarts Explorer when allowed and reports reboot-required features' {
+        Mock Stop-Process {}
+        Mock Get-RebootFeatureLabels { @('Disable telemetry') }
+
+        Invoke-RestartExplorer
+
+        Should -Invoke Stop-Process -Times 1 -Exactly -ParameterFilter { $processName -eq 'Explorer' -and $Force }
+        Should -Invoke Get-RebootFeatureLabels -Times 1 -Exactly
+    }
+}
+
+Describe 'Resolve-UserSid' {
+    BeforeEach {
+        $script:ResolvedUserSidCache = @{}
+        $script:MachineDomainJoinStateKnown = $null
+        $script:MachineIsDomainJoined = $false
+        $script:MachineNetBiosDomain = ''
+    }
+
+    It 'builds domain-aware candidate forms and compares profile folder leaves' {
+        Mock Get-ProfileFolderDomainSuffix { 'CONTOSO' }
+
+        Get-UserNameMatchCandidates -Value 'CONTOSO\Alice' | Should -Be @('CONTOSO\Alice', 'Alice', 'Alice.CONTOSO')
+        Test-UserNameMatchesProfileLeaf -UserName 'CONTOSO\Alice' -ProfileLeaf 'Alice.CONTOSO' | Should -BeTrue
+    }
+
+    It 'prefers the NetBIOS domain source and falls back to the DNS label' {
+        Mock Get-CimInstance { [PSCustomObject]@{ DomainName = 'CONTOSO'; DomainControllerName = '\\dc01.contoso.com' } }
+        Resolve-NetBiosDomainName -RawDomain 'contoso.com' | Should -Be 'CONTOSO'
+
+        Mock Get-CimInstance { throw 'CIM unavailable' }
+        Resolve-NetBiosDomainName -RawDomain 'contoso.com' | Should -Be 'contoso'
+    }
+
+    It 'stores and retrieves resolved SIDs through normalized cache keys' {
+        Set-ResolvedUserSidCache -Candidates @('Alice', 'CONTOSO\Alice') -Sid 'S-1-5-21-1000'
+
+        Get-CachedResolvedUserSid -Candidates @('contoso\alice') | Should -Be 'S-1-5-21-1000'
+    }
+
+    It 'returns a local-user SID before falling back to CIM' {
+        Mock Get-Command { [PSCustomObject]@{ Name = 'Get-LocalUser' } } -ParameterFilter { $Name -eq 'Get-LocalUser' }
+        Mock Get-LocalUser { [PSCustomObject]@{ SID = [PSCustomObject]@{ Value = 'S-1-5-21-1000' } } }
+        Mock Get-CimInstance { throw 'CIM should not be queried' }
+
+        Try-ResolveSidByLocalLookup -Candidates @('Alice') | Should -Be 'S-1-5-21-1000'
+        Should -Invoke Get-CimInstance -Times 0 -Exactly
+    }
+
+    It 'recovers a workgroup SID from a matching ProfileList folder' {
+        Mock Test-MachineIsDomainJoined { $false }
+        Mock Get-ChildItem { [PSCustomObject]@{ PSPath = 'Registry::ProfileList\S-1-5-21-1000'; PSChildName = 'S-1-5-21-1000' } }
+        Mock Get-ItemPropertyValue { 'C:\Users\Alice' }
+
+        Try-ResolveSidFromProfileList -Candidates @('Alice') | Should -Be 'S-1-5-21-1000'
+    }
+
+    It 'constructs user contexts and resolves a workgroup SID through NTAccount' {
+        $context = New-ResolvedUserContext -UserName 'Alice' -UserSid 'S-1-5-21-1000' -ProfilePath 'C:\Users\Alice'
+        $context.UserName | Should -Be 'Alice'
+        $context.UserSid | Should -Be 'S-1-5-21-1000'
+
+        Mock Get-CachedResolvedUserSid { $null }
+        Mock Test-MachineIsDomainJoined { $false }
+        Mock Try-ResolveSidByNtAccount { 'S-1-5-21-1000' }
+        Mock Set-ResolvedUserSidCache {}
+
+        Resolve-UserSid -UserName 'Alice' | Should -Be 'S-1-5-21-1000'
+        Should -Invoke Try-ResolveSidByNtAccount -Times 1 -Exactly -ParameterFilter { $UserName -eq 'Alice' }
+    }
+
+    It 'does not qualify blank names or process UI events without a GUI window' {
+        Get-QualifiedProcessIdentityName -Candidate '' | Should -BeNullOrEmpty
+        $script:GuiWindow = $null
+        { Invoke-DoEvents } | Should -Not -Throw
+    }
+}

Tests/Restore-BackupDialogFeatureLists.Tests.ps1

@@ -0,0 +1,57 @@
+BeforeAll {
+    . (Join-Path $PSScriptRoot '..\Scripts\GUI\Restore-BackupDialogFeatureLists.ps1')
+}
+
+Describe 'New-RestoreDialogState' {
+    BeforeEach {
+        $script:Features = @{
+            RegistryFeature = [PSCustomObject]@{ Label = 'Registry feature'; Category = 'Privacy'; RegistryKey = 'RegistryFeature.reg' }
+            CustomFeature = [PSCustomObject]@{ Label = 'Custom feature'; Category = 'Privacy'; RegistryKey = '' }
+            HiddenFeature = [PSCustomObject]@{ Label = 'Hidden feature'; Category = ''; RegistryKey = 'HiddenFeature.reg' }
+        }
+    }
+
+    It 'creates a dialog state with the supplied values' {
+        $backup = [PSCustomObject]@{ SelectedFeatures = @('RegistryFeature') }
+
+        $state = New-RestoreDialogState -Result 'OK' -SelectedFile 'C:\Backups\backup.json' -Backup $backup
+
+        $state.Result | Should -Be 'OK'
+        $state.SelectedFile | Should -Be 'C:\Backups\backup.json'
+        $state.Backup | Should -Be $backup
+    }
+
+    It 'looks up feature definitions and resolves display labels with fallbacks' {
+        Get-RestoreDialogFeatureDefinition -FeatureId 'RegistryFeature' -Features $script:Features | Should -Be $script:Features.RegistryFeature
+        Get-RestoreDialogFeatureDefinition -FeatureId 'MissingFeature' -Features $script:Features | Should -BeNullOrEmpty
+        Get-RestoreDialogFeatureDisplayLabel -FeatureId 'RegistryFeature' -Features $script:Features | Should -Be 'Registry feature'
+        Get-RestoreDialogFeatureDisplayLabel -FeatureId 'MissingFeature' -Features $script:Features | Should -Be 'MissingFeature'
+        Get-RestoreDialogFeatureDisplayLabel -FeatureId '' -Features $script:Features | Should -Be 'Unknown feature'
+    }
+
+    It 'identifies visible, automatically revertible features' {
+        Test-RestoreDialogFeatureCanAutoRevert -FeatureId 'RegistryFeature' -Features $script:Features | Should -BeTrue
+        Test-RestoreDialogFeatureCanAutoRevert -FeatureId 'CustomFeature' -Features $script:Features | Should -BeFalse
+        Test-RestoreDialogFeatureVisibleInOverview -FeatureId 'RegistryFeature' -Features $script:Features | Should -BeTrue
+        Test-RestoreDialogFeatureVisibleInOverview -FeatureId 'HiddenFeature' -Features $script:Features | Should -BeFalse
+    }
+
+    It 'deduplicates and combines forward and undo feature IDs' {
+        $backup = [PSCustomObject]@{
+            SelectedFeatures = @('RegistryFeature', 'registryfeature', '', 'CustomFeature')
+            SelectedUndoFeatures = @('CustomFeature', 'HiddenFeature', 'hiddenfeature')
+        }
+
+        Get-SelectedForwardFeatureIdsFromBackup -SelectedBackup $backup | Should -Be @('RegistryFeature', 'CustomFeature')
+        Get-SelectedUndoFeatureIdsFromBackup -SelectedBackup $backup | Should -Be @('CustomFeature', 'HiddenFeature')
+        Get-CombinedSelectedFeatureIdsFromBackup -SelectedBackup $backup | Should -Be @('RegistryFeature', 'CustomFeature', 'HiddenFeature')
+        Get-SelectedFeatureIdsFromBackup -SelectedBackup $backup | Should -Be @('RegistryFeature', 'CustomFeature', 'HiddenFeature')
+    }
+
+    It 'separates visible feature labels into revertible and manual lists' {
+        $lists = Get-RestoreBackupFeatureLists -SelectedFeatureIds @('RegistryFeature', 'CustomFeature', 'HiddenFeature', 'MissingFeature') -Features $script:Features
+
+        $lists.Revertible.DisplayText | Should -Be '- Registry feature'
+        $lists.NonRevertible.DisplayText | Should -Be '- Custom feature'
+    }
+}

Tests/Restore-RegistryApplyState.Tests.ps1

@@ -0,0 +1,71 @@
+BeforeAll {
+    $restoreApplyStateScriptPath = Join-Path $PSScriptRoot '..\Scripts\Features\Restore-RegistryApplyState.ps1'
+    . $restoreApplyStateScriptPath
+}
+
+Describe 'Convert-RegistryValueKindFromBackup' {
+    It 'defaults a missing kind to String' {
+        Convert-RegistryValueKindFromBackup -KindName $null | Should -Be ([Microsoft.Win32.RegistryValueKind]::String)
+    }
+
+    It '<Case>' -ForEach @(
+        @{ Case = 'parses registry kinds case-insensitively'; KindName = 'dword'; Expected = [Microsoft.Win32.RegistryValueKind]::DWord; ExpectedError = $null }
+        @{ Case = 'rejects an invalid registry kind'; KindName = 'NotARegistryValueKind'; Expected = $null; ExpectedError = 'Unsupported registry value kind in backup: NotARegistryValueKind' }
+    ) {
+        if ($ExpectedError) {
+            { Convert-RegistryValueKindFromBackup -KindName $KindName } | Should -Throw $ExpectedError
+        }
+        else {
+            Convert-RegistryValueKindFromBackup -KindName $KindName | Should -Be $Expected
+        }
+    }
+}
+
+Describe 'Convert-RegistryValueDataFromBackup' {
+    It 'preserves the bit pattern of an unsigned <Kind>' -ForEach @(
+        @{ Kind = [Microsoft.Win32.RegistryValueKind]::DWord; Data = [uint32]::MaxValue; Expected = -1 }
+        @{ Kind = [Microsoft.Win32.RegistryValueKind]::QWord; Data = [uint64]::MaxValue; Expected = -1L }
+    ) {
+        Convert-RegistryValueDataFromBackup -Kind $Kind -Data $Data | Should -Be $Expected
+    }
+
+    It 'converts <Case>' -ForEach @(
+        @{ Case = 'a multi-string value'; Kind = [Microsoft.Win32.RegistryValueKind]::MultiString; Data = @(1, 'two'); Expected = @('1', 'two'); ExpectNull = $false }
+        @{ Case = 'a binary value'; Kind = [Microsoft.Win32.RegistryValueKind]::Binary; Data = @('1', 255); Expected = [byte[]](1, 255); ExpectNull = $false }
+        @{ Case = 'a null string to an empty string'; Kind = [Microsoft.Win32.RegistryValueKind]::String; Data = $null; Expected = ''; ExpectNull = $false }
+    ) {
+        $result = Convert-RegistryValueDataFromBackup -Kind $Kind -Data $Data
+        if ($ExpectNull) {
+            $result | Should -BeNullOrEmpty
+        }
+        else {
+            $result | Should -Be $Expected
+            if ($Kind -eq [Microsoft.Win32.RegistryValueKind]::MultiString) {
+                $result.GetType() | Should -Be ([string[]])
+            }
+        }
+    }
+
+    It 'rejects binary backup data that cannot be represented as bytes' {
+        { Convert-RegistryValueDataFromBackup -Kind ([Microsoft.Win32.RegistryValueKind]::Binary) -Data @(-1, 256, 'invalid') } |
+            Should -Throw 'Invalid binary registry data in backup*'
+    }
+
+    It 'preserves an empty binary value as a byte array' {
+        $result = Convert-RegistryValueDataFromBackup -Kind ([Microsoft.Win32.RegistryValueKind]::Binary) -Data $null
+        $result | Should -BeNullOrEmpty
+        $result.GetType() | Should -Be ([byte[]])
+    }
+
+}
+
+Describe 'Convert-BackupDataToByteArray' {
+    It 'rejects <Case>' -ForEach @(
+        @{ Case = 'an object value'; Data = [PSCustomObject]@{ Value = 1 } }
+        @{ Case = 'a negative byte'; Data = @(-1) }
+        @{ Case = 'a byte greater than 255'; Data = @(256) }
+        @{ Case = 'non-numeric input'; Data = @('invalid') }
+    ) {
+        Convert-BackupDataToByteArray -Data $Data | Should -BeNullOrEmpty
+    }
+}

Tests/Restore-RegistryBackup.Tests.ps1

@@ -0,0 +1,147 @@
+BeforeAll {
+    function Test-RunningAsSystem { $false }
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Registry-PathHelpers.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Get-FriendlyRegistryBackupTarget.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Resolve-UserProfilePath.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Test-TargetUserName.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Registry-BackupValidation.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Restore-RegistryApplyState.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Features\Restore-RegistryBackup.ps1')
+    $script:JsonFixturePath = Join-Path $PSScriptRoot 'TestData\JsonFileLoading'
+}
+
+Describe 'Import-RegistryBackup' {
+    It 'loads JSON and passes the parsed backup to normalization' {
+        Mock ConvertTo-NormalizedRegistryBackup { [PSCustomObject]@{ Target = 'DefaultUserProfile' } }
+
+        $result = Import-RegistryBackup -FilePath (Join-Path $script:JsonFixturePath 'RegistryBackup.Valid.json')
+
+        $result.Target | Should -Be 'DefaultUserProfile'
+        Should -Invoke ConvertTo-NormalizedRegistryBackup -Times 1 -Exactly
+    }
+
+    It 'parses and normalizes registry snapshots from a real backup structure' {
+        Mock Test-UserNameMatch { $true }
+        Mock Test-RegistryBackupMatchesSelectedFeatures { @() }
+
+        $result = Import-RegistryBackup -FilePath (Join-Path $script:JsonFixturePath 'RegistryBackup.RealStructure.json')
+
+        $result.Target | Should -Be 'CurrentUser:fixture-user'
+        $result.SelectedFeatures | Should -Be @('RemoveApps', 'DisableStickyKeys')
+        $result.SelectedUndoFeatures | Should -Be 'DisableTransparency'
+        $result.RegistryKeys | Should -HaveCount 2
+        $result.RegistryKeys[0].Path | Should -Be 'HKEY_CURRENT_USER\Control Panel\Accessibility\StickyKeys'
+        $result.RegistryKeys[0].Values[0].Name | Should -Be 'Flags'
+        $result.RegistryKeys[0].Values[0].Kind | Should -Be 'String'
+        $result.RegistryKeys[0].Values[0].Data | Should -Be '510'
+        $result.RegistryKeys[1].Path | Should -Be 'HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize'
+        $result.RegistryKeys[1].Values[0].Name | Should -Be 'EnableTransparency'
+        $result.RegistryKeys[1].Values[0].Kind | Should -Be 'DWord'
+        $result.RegistryKeys[1].Values[0].Data | Should -Be 0
+        Should -Invoke Test-RegistryBackupMatchesSelectedFeatures -Times 1 -Exactly
+    }
+
+    It 'rejects <Case>' -ForEach @(
+        @{ Case = 'a missing backup file'; FileName = 'missing.json'; ExpectedError = 'Backup file was not found:*' }
+        @{ Case = 'an invalid JSON backup file'; FileName = 'RegistryBackup.Invalid.json'; ExpectedError = $null }
+    ) {
+        $path = Join-Path $script:JsonFixturePath $FileName
+        $errorPattern = if ($null -ne $ExpectedError) { $ExpectedError } else { "Failed to read backup file '$path'. The file is not valid JSON." }
+
+        { Import-RegistryBackup -FilePath $path } | Should -Throw $errorPattern
+    }
+}
+
+Describe 'ConvertTo-NormalizedRegistryBackup' {
+    BeforeEach {
+        $script:Features = @{ Example = [PSCustomObject]@{ FeatureId = 'Example'; RegistryKey = 'Example.reg' } }
+        Mock Test-RegistryBackupMatchesSelectedFeatures { @() }
+        Mock Write-Error {}
+    }
+
+    It 'normalizes a valid legacy backup without undo selections' {
+        $backup = [PSCustomObject]@{
+            Version = '1.0'; BackupType = 'RegistryState'; Target = 'DefaultUserProfile'
+            CreatedAt = '2026-01-01T00:00:00.0000000Z'; CreatedBy = 'Win11Debloat'; ComputerName = 'PC'
+            SelectedFeatures = @('Example', 'example'); RegistryKeys = @()
+        }
+
+        $result = ConvertTo-NormalizedRegistryBackup -Backup $backup
+
+        $result.Target | Should -Be 'DefaultUserProfile'
+        $result.SelectedFeatures -is [array] | Should -BeTrue
+        $result.SelectedFeatures | Should -Be 'Example'
+        $result.SelectedUndoFeatures | Should -BeNullOrEmpty
+        Should -Invoke Test-RegistryBackupMatchesSelectedFeatures -Times 1 -Exactly
+    }
+
+    It 'aggregates invalid metadata and does not attempt allow-list validation without feature IDs' {
+        $backup = [PSCustomObject]@{ Version = '2.0'; BackupType = 'Other'; Target = 'Unknown'; RegistryKeys = @() }
+
+        { ConvertTo-NormalizedRegistryBackup -Backup $backup } | Should -Throw 'Validation failed with * errors. See console output for details.'
+
+        Should -Invoke Write-Error -Times 1 -Exactly
+        Should -Invoke Test-RegistryBackupMatchesSelectedFeatures -Times 0 -Exactly
+    }
+
+    It 'reports an invalid user target as a validation failure' {
+        Mock Test-TargetUserName { [PSCustomObject]@{ IsValid = $false } }
+        $backup = [PSCustomObject]@{
+            Version = '1.0'; BackupType = 'RegistryState'; Target = 'User:bad/user'
+            SelectedFeatures = @('Example'); RegistryKeys = @()
+        }
+
+        { ConvertTo-NormalizedRegistryBackup -Backup $backup } | Should -Throw "Validation failed: Invalid user 'User:bad/user'"
+    }
+
+    It 'does not allow current-user backup restore when running as SYSTEM' {
+        Mock Test-RunningAsSystem { $true }
+        $backup = [PSCustomObject]@{
+            Version = '1.0'; BackupType = 'RegistryState'; Target = 'CurrentUser:Alice'
+            SelectedFeatures = @('Example'); RegistryKeys = @()
+        }
+
+        { ConvertTo-NormalizedRegistryBackup -Backup $backup } |
+            Should -Throw "Validation failed: Backup was made for 'Alice' and is user-scoped*"
+    }
+}
+
+Describe 'Restore-RegistryBackupState' {
+    BeforeEach {
+        $script:Params = @{}
+        Mock Get-FriendlyRegistryBackupTarget { 'friendly target' }
+        Mock Restore-RegistryKeySnapshot {}
+        Mock Invoke-WithLoadedRestoreHive {}
+        Mock Write-Host {}
+        $script:backup = [PSCustomObject]@{ Target = 'CurrentUser:Tester'; RegistryKeys = @([PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\One' }, [PSCustomObject]@{ Path = 'HKEY_CURRENT_USER\Software\Two' }) }
+    }
+
+    It 'restores every root snapshot directly for the current user' {
+        (Restore-RegistryBackupState -Backup $script:backup).Result | Should -BeTrue
+
+        Should -Invoke Restore-RegistryKeySnapshot -Times 2 -Exactly
+        Should -Invoke Invoke-WithLoadedRestoreHive -Times 0 -Exactly
+    }
+
+    It 'delegates default-profile restores through the loaded hive wrapper' {
+        $script:backup.Target = 'DefaultUserProfile'
+        Mock Invoke-WithLoadedRestoreHive {
+            param($Target, $ScriptBlock, $ArgumentObject)
+            & $ScriptBlock $ArgumentObject
+        }
+
+        (Restore-RegistryBackupState -Backup $script:backup).Result | Should -BeTrue
+
+        Should -Invoke Invoke-WithLoadedRestoreHive -Times 1 -Exactly -ParameterFilter { $Target -eq 'DefaultUserProfile' }
+        Should -Invoke Restore-RegistryKeySnapshot -Times 2 -Exactly
+    }
+
+    It 'honors WhatIf without restoring snapshots or loading a hive' {
+        $script:Params = @{ WhatIf = $true }
+
+        (Restore-RegistryBackupState -Backup $script:backup).Result | Should -BeTrue
+
+        Should -Invoke Restore-RegistryKeySnapshot -Times 0 -Exactly
+        Should -Invoke Invoke-WithLoadedRestoreHive -Times 0 -Exactly
+    }
+}

Tests/Settings-And-Apps-FileIO.Tests.ps1

@@ -0,0 +1,189 @@
+BeforeAll {
+    function Wait-ForKeyPress {}
+    function Test-AppInWingetList { param($appId, $InstalledList) $false }
+
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-JsonFile.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\Helpers\Add-Parameter.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Save-ToFile.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-Settings.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Save-Settings.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-AppsFromFile.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-AppDetailsFromJson.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Import-AppPresetsFromJson.ps1')
+    . (Join-Path $PSScriptRoot '..\Scripts\FileIO\Get-ValidatedAppList.ps1')
+    $script:JsonFixturePath = Join-Path $PSScriptRoot 'TestData\JsonFileLoading'
+}
+
+Describe 'Import-Settings' {
+    BeforeEach {
+        $script:Params = @{}
+        $script:ModernStandbySupported = $false
+        $script:Features = @{
+            Supported = [PSCustomObject]@{ FeatureId = 'Supported'; MinVersion = 22000; MaxVersion = 30000 }
+            TooNew = [PSCustomObject]@{ FeatureId = 'TooNew'; MinVersion = 99999; MaxVersion = $null }
+            DisableModernStandbyNetworking = [PSCustomObject]@{ FeatureId = 'DisableModernStandbyNetworking'; MinVersion = $null; MaxVersion = $null }
+        }
+        Mock Get-ItemPropertyValue { 22631 }
+        Mock Add-Parameter {}
+        Mock Write-Error {}
+    }
+
+    It 'loads enabled, known, compatible settings and skips all other entries' {
+        Import-Settings -filePath (Join-Path $script:JsonFixturePath 'DefaultSettings.Valid.json')
+
+        Should -Invoke Add-Parameter -Times 1 -Exactly -ParameterFilter { $parameterName -eq 'Supported' -and $value -eq 'configured' }
+    }
+
+    It 'throws when <Case>' -ForEach @(
+        @{ Case = 'the last-used settings JSON is invalid'; FileName = 'LastUsedSettings.Invalid.json'; WriteErrorCalls = 1 }
+        @{ Case = 'the default settings file has no Settings property'; FileName = 'DefaultSettings.MissingSettings.json'; WriteErrorCalls = 0 }
+    ) {
+        $path = Join-Path $script:JsonFixturePath $FileName
+
+        {
+            & {
+                $ErrorActionPreference = 'Continue'
+                Import-Settings -filePath $path
+            }
+        } | Should -Throw "Failed to load settings from $FileName"
+        Should -Invoke Add-Parameter -Times 0 -Exactly
+        Should -Invoke Write-Error -Times $WriteErrorCalls -Exactly
+    }
+}
+
+Describe 'Save-Settings' {
+    BeforeEach {
+        $script:SavedSettingsFilePath = Join-Path $TestDrive 'LastUsedSettings.json'
+        $script:ControlParams = @('Silent', 'WhatIf')
+        $script:Features = @{ Feature = [PSCustomObject]@{ FeatureId = 'Feature' } }
+        Mock Save-ToFile { $true }
+        Mock Write-Host {}
+        Mock Write-Output {}
+    }
+
+    It 'saves only feature parameters and excludes control or unknown parameters' {
+        $script:Params = @{ Feature = 'configured'; Silent = $true; Unknown = 42 }
+
+        Save-Settings
+
+        Should -Invoke Save-ToFile -Times 1 -Exactly -ParameterFilter {
+            $FilePath -eq $script:SavedSettingsFilePath -and
+            @($Config.Settings).Count -eq 1 -and
+            $Config.Settings[0].Name -eq 'Feature' -and
+            $Config.Settings[0].Value -eq 'configured'
+        }
+    }
+
+    It 'does not persist in WhatIf mode' {
+        $script:Params = @{ Feature = $true; WhatIf = $true }
+
+        Save-Settings
+
+        Should -Invoke Save-ToFile -Times 0 -Exactly
+    }
+
+    It 'reports a persistence failure without throwing' {
+        $script:Params = @{ Feature = $true }
+        Mock Save-ToFile { $false }
+
+        { Save-Settings } | Should -Not -Throw
+        Should -Invoke Write-Host -Times 1 -Exactly -ParameterFilter { $Object -like 'Error:*' }
+    }
+}
+
+Describe 'Import-AppsFromFile' {
+    It 'returns selected IDs, trims whitespace, and supports scalar and array AppId values' {
+        $path = Join-Path $TestDrive 'apps.json'
+        '{"Apps":[{"AppId":" One.App ","SelectedByDefault":true},{"AppId":["Two.App","  "],"SelectedByDefault":true},{"AppId":"Ignored.App","SelectedByDefault":false}]}' |
+            Set-Content -LiteralPath $path -Encoding UTF8
+
+        @(Import-AppsFromFile -appsFilePath $path) | Should -Be @('One.App', 'Two.App')
+    }
+
+    It 'returns an empty collection for a missing file' {
+        @(Import-AppsFromFile -appsFilePath (Join-Path $TestDrive 'missing.json')) | Should -HaveCount 0
+    }
+
+    It 'reports invalid JSON and invokes the CLI acknowledgement hook' {
+        $path = Join-Path $TestDrive 'invalid-apps.json'
+        'not json' | Set-Content -LiteralPath $path
+        Mock Write-Error {}
+        Mock Wait-ForKeyPress {}
+
+        @(Import-AppsFromFile -appsFilePath $path) | Should -HaveCount 0
+        Should -Invoke Write-Error -Times 1 -Exactly
+        Should -Invoke Wait-ForKeyPress -Times 1 -Exactly
+    }
+}
+
+Describe 'Get-ValidatedAppList' {
+    It 'normalizes wildcard selections and skips unsupported applications' {
+        Mock Import-AppDetailsFromJson { @([PSCustomObject]@{ AppId = @('One.App', 'Two.App') }) }
+        Mock Write-Host {}
+
+        @(Get-ValidatedAppList -appsList @('*One.App*', ' Missing.App ')) | Should -Be @('One.App')
+        Should -Invoke Write-Host -Times 1 -Exactly -ParameterFilter { $Object -like "*Missing.App*" }
+    }
+}
+
+Describe 'Import-AppDetailsFromJson' {
+    BeforeEach {
+        $script:AppsListFilePath = Join-Path $TestDrive 'Apps.json'
+        '{"Apps":[{"AppId":["One.App","Alias.App"],"FriendlyName":"One","SelectedByDefault":true,"RemovalMethod":"WinGet"},{"AppId":"Two.App","SelectedByDefault":false},{"AppId":"  ","SelectedByDefault":true}],"Presets":[{"Name":"Minimal","AppIds":["One.App"]}]}' |
+            Set-Content -LiteralPath $script:AppsListFilePath -Encoding UTF8
+    }
+
+    It 'projects app metadata, defaults removal method, and honors initial checked state' {
+        $apps = @(Import-AppDetailsFromJson -InitialCheckedFromJson)
+
+        $apps | Should -HaveCount 2
+        $apps[0].DisplayName | Should -Be 'One (One.App, Alias.App)'
+        $apps[0].IsChecked | Should -BeTrue
+        $apps[0].RemovalMethod | Should -Be 'WinGet'
+        $apps[1].FriendlyName | Should -Be 'Two.App'
+        $apps[1].RemovalMethod | Should -Be 'Appx'
+        $apps[1].AppId -is [array] | Should -BeTrue
+        @($apps[1].AppId) | Should -HaveCount 1
+    }
+
+    It 'skips missing, blank, and non-string app IDs without failing the complete catalog' {
+        '{"Apps":[{"AppId":null},{"FriendlyName":"Missing"},{"AppId":42},{"AppId":[" Valid.App ",null,{},""]}]}' |
+            Set-Content -LiteralPath $script:AppsListFilePath -Encoding UTF8
+
+        $apps = @(Import-AppDetailsFromJson)
+
+        $apps | Should -HaveCount 1
+        $apps[0].AppId -is [array] | Should -BeTrue
+        $apps[0].AppId | Should -Be @('Valid.App')
+    }
+
+    It 'filters to installed apps using Appx and winget detection' {
+        Mock Get-AppxPackage { param($Name) if ($Name -eq 'Two.App') { [PSCustomObject]@{ Name = $Name } } }
+        Mock Test-AppInWingetList { $false }
+
+        $apps = @(Import-AppDetailsFromJson -OnlyInstalled -InstalledList @())
+
+        $apps | Should -HaveCount 1
+        $apps[0].AppId | Should -Be 'Two.App'
+    }
+
+    It 'loads presets and preserves their ID arrays' {
+        $presets = @(Import-AppPresetsFromJson)
+
+        $presets | Should -HaveCount 1
+        $presets[0].Name | Should -Be 'Minimal'
+        $presets[0].AppIds -is [array] | Should -BeTrue
+        $presets[0].AppIds | Should -Be 'One.App'
+    }
+
+    It 'returns empty collections and reports malformed JSON' {
+        'not json' | Set-Content -LiteralPath $script:AppsListFilePath
+        Mock Write-Error {}
+        Mock Write-Warning {}
+
+        @(Import-AppDetailsFromJson) | Should -HaveCount 0
+        @(Import-AppPresetsFromJson) | Should -HaveCount 0
+        Should -Invoke Write-Error -Times 1 -Exactly
+        Should -Invoke Write-Warning -Times 1 -Exactly
+    }
+}