Add option to show & undo applied tweaks

Schemas/MainWindow.xaml

@@ -732,6 +732,8 @@
                                         <ColumnDefinition Width="Auto"/>
                                         <ColumnDefinition Width="*"/>
                                         <ColumnDefinition Width="Auto"/>
+                                        <ColumnDefinition Width="10"/>
+                                        <ColumnDefinition Width="Auto"/>
                                     </Grid.ColumnDefinitions>
                                     
                                     <StackPanel Grid.Column="0" Orientation="Horizontal">
@@ -798,7 +800,9 @@
                                         </Popup>
                                     </StackPanel>
 
-                                    <Border x:Name="TweakSearchBorder" Grid.Column="2">
+                                    <CheckBox x:Name="ShowCurrentlyAppliedTweaksCheckBox" Grid.Column="2" Content="Check applied tweaks" IsChecked="True" Foreground="{DynamicResource FgColor}" VerticalAlignment="Center" AutomationProperties.Name="Check applied tweaks" ToolTip="Check all tweaks currently active on this system. Unchecking clears all selections."/>
+
+                                    <Border x:Name="TweakSearchBorder" Grid.Column="4">
                                         <Border.Style>
                                             <Style TargetType="Border" BasedOn="{StaticResource SearchBoxBorderStyle}">
                                                 <Style.Triggers>

Scripts/Features/BackupRegistryFeatureSelection.ps1

@@ -14,8 +14,7 @@ function Get-FeatureId {
 
 function Get-RegistryBackedFeatures {
     param(
-        [Parameter(Mandatory)]
-        [object[]]$Features
+        [object[]]$Features = @()
     )
 
     return @($Features | Where-Object { -not [string]::IsNullOrWhiteSpace([string]$_.RegistryKey) })

Scripts/Features/BackupRegistrySnapshotCapture.ps1

@@ -1,7 +1,6 @@
 function Get-RegistryBackupCapturePlans {
     param(
-        [Parameter(Mandatory)]
-        [object[]]$SelectedRegistryFeatures,
+        [object[]]$SelectedRegistryFeatures = @(),
         [switch]$UseSysprepRegFiles
     )
 
@@ -59,8 +58,7 @@ function Get-RegistryBackupCapturePlans {
 
 function Get-RegistrySnapshotsForBackup {
     param(
-        [Parameter(Mandatory)]
-        [object[]]$CapturePlans
+        [object[]]$CapturePlans = @()
     )
 
     if ($CapturePlans.Count -eq 0) {

Scripts/Features/BackupRegistryState.ps1

@@ -1,11 +1,14 @@
 function New-RegistrySettingsBackup {
     param(
-        [string[]]$ActionableKeys
+        [string[]]$ActionableKeys,
+        [object[]]$ExtraFeatures = @()
     )
 
     $ActionableKeys = @($ActionableKeys)
-    $selectedFeatures = Get-SelectedFeatures -ActionableKeys $ActionableKeys
-    if (@($selectedFeatures | Where-Object { -not [string]::IsNullOrWhiteSpace([string]$_.RegistryKey) }).Count -eq 0) {
+    $selectedFeatures = @(Get-SelectedFeatures -ActionableKeys $ActionableKeys)
+    $undoFeatures = @($ExtraFeatures | Where-Object { $_ -ne $null })
+    $allFeatures = @($selectedFeatures) + @($undoFeatures)
+    if (@($allFeatures | Where-Object { -not [string]::IsNullOrWhiteSpace([string]$_.RegistryKey) }).Count -eq 0) {
         return $null
     }
 
@@ -18,7 +21,7 @@ function New-RegistrySettingsBackup {
     $backupFileName = 'Win11Debloat-RegistryBackup-{0}.json' -f $timestamp.ToString('yyyyMMdd_HHmmss')
     $backupFilePath = Join-Path $backupDirectory $backupFileName
 
-    $backupConfig = Get-RegistryBackupPayload -SelectedFeatures $selectedFeatures -CreatedAt $timestamp
+    $backupConfig = Get-RegistryBackupPayload -SelectedFeatures $selectedFeatures -UndoFeatures $undoFeatures -CreatedAt $timestamp
     if (-not (SaveToFile -Config $backupConfig -FilePath $backupFilePath -MaxDepth 25)) {
         throw "Failed to save registry backup to '$backupFilePath'"
     }
@@ -55,8 +58,8 @@ function Get-SelectedFeatures {
 
 function Get-RegistryBackupPayload {
     param(
-        [Parameter(Mandatory)]
-        [object[]]$SelectedFeatures,
+        [object[]]$SelectedFeatures = @(),
+        [object[]]$UndoFeatures = @(),
         [Parameter(Mandatory)]
         [datetime]$CreatedAt
     )
@@ -71,11 +74,22 @@ function Get-RegistryBackupPayload {
         }
     }
 
-    $selectedRegistryFeatures = Get-RegistryBackedFeatures -Features $SelectedFeatures
-    $capturePlans = Get-RegistryBackupCapturePlans -SelectedRegistryFeatures $SelectedRegistryFeatures
+    $selectedUndoFeatureIds = New-Object System.Collections.Generic.List[string]
+    $seenUndoFeatureIds = New-Object 'System.Collections.Generic.HashSet[string]' ([System.StringComparer]::OrdinalIgnoreCase)
+    foreach ($feature in $UndoFeatures) {
+        $featureId = Get-FeatureId -Feature $feature
+
+        if ($seenUndoFeatureIds.Add($featureId)) {
+            $selectedUndoFeatureIds.Add($featureId)
+        }
+    }
+
+    $allCapturableFeatures = @($SelectedFeatures) + @($UndoFeatures)
+    $selectedRegistryFeatures = @(Get-RegistryBackedFeatures -Features $allCapturableFeatures)
+    $capturePlans = @(Get-RegistryBackupCapturePlans -SelectedRegistryFeatures $selectedRegistryFeatures)
     $registryKeys = @(Get-RegistrySnapshotsForBackup -CapturePlans $capturePlans)
 
-    return @{
+    $backupPayload = @{
         Version = '1.0'
         BackupType = 'RegistryState'
         CreatedAt = $CreatedAt.ToString('o')
@@ -85,4 +99,10 @@ function Get-RegistryBackupPayload {
         SelectedFeatures = @($selectedFeatureIds)
         RegistryKeys = @($registryKeys)
     }
+
+    if ($selectedUndoFeatureIds.Count -gt 0) {
+        $backupPayload['SelectedUndoFeatures'] = @($selectedUndoFeatureIds)
+    }
+
+    return $backupPayload
 }

Scripts/Features/DisableStoreSearchSuggestions.ps1

@@ -49,4 +49,126 @@ function DisableStoreSearchSuggestions {
     Set-Acl -Path $StoreAppsDatabase -AclObject $Acl | Out-Null
 
     Write-Host "Disabled Microsoft Store search suggestions for user $userName"
+}
+
+function EnableStoreSearchSuggestionsForAllUsers {
+    # Get path to Store app database for all users
+    $userPathString = GetUserDirectory -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 $usersStoreDbPaths) {
+        EnableStoreSearchSuggestions ($storeDbPath.FullName + "\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db")
+    }
+
+    # Also re-enable for the default user profile
+    $defaultStoreDbPath = GetUserDirectory -userName "Default" -fileName "AppData\Local\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db" -exitIfPathNotFound $false
+    EnableStoreSearchSuggestions $defaultStoreDbPath
+}
+
+function EnableStoreSearchSuggestions {
+    param (
+        $StoreAppsDatabase = "$env:LocalAppData\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db"
+    )
+
+    # Change path to correct user if a user was specified
+    if ($script:Params.ContainsKey("User")) {
+        $StoreAppsDatabase = GetUserDirectory -userName "$(GetUserName)" -fileName "AppData\Local\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db" -exitIfPathNotFound $false
+    }
+
+    $userName = [regex]::Match($StoreAppsDatabase, '(?:Users\\)([^\\]+)(?:\\AppData)').Groups[1].Value
+    if (-not $userName) { $userName = '<unknown>' }
+
+    if (-not (Test-Path -Path $StoreAppsDatabase)) {
+        Write-Host "Store app database not found for user $userName, nothing to undo"
+        return
+    }
+
+    # Ensure we can modify/delete the file even if restrictive ACLs were set.
+    $global:LASTEXITCODE = 0
+    takeown /F "$StoreAppsDatabase" /A | Out-Null
+    icacls "$StoreAppsDatabase" /grant *S-1-5-32-544:F /C | Out-Null
+
+    try {
+        $acl = Get-Acl -Path $StoreAppsDatabase
+        $denyRules = @(
+            $acl.Access | Where-Object {
+                $_.IdentityReference -eq 'Everyone' -and
+                $_.AccessControlType -eq [System.Security.AccessControl.AccessControlType]::Deny -and
+                (($_.FileSystemRights -band [System.Security.AccessControl.FileSystemRights]::FullControl) -ne 0)
+            }
+        )
+
+        foreach ($denyRule in $denyRules) {
+            $null = $acl.RemoveAccessRuleSpecific($denyRule)
+        }
+
+        Set-Acl -Path $StoreAppsDatabase -AclObject $acl | Out-Null
+    }
+    catch {
+        Write-Warning "Failed to normalize ACL for store database '$StoreAppsDatabase': $($_.Exception.Message)"
+    }
+
+    try {
+        Remove-Item -Path $StoreAppsDatabase -Force -ErrorAction Stop
+        Write-Host "Re-enabled Microsoft Store search suggestions for user $userName"
+    }
+    catch {
+        throw "Failed to remove '$StoreAppsDatabase' while undoing Microsoft Store search suggestions for user $userName. $($_.Exception.Message)"
+    }
+}
+
+function Test-StoreSearchSuggestionsDisabled {
+    param(
+        [Parameter(Mandatory)]
+        [string]$StoreAppsDatabase
+    )
+
+    if (-not (Test-Path -Path $StoreAppsDatabase)) {
+        return $false
+    }
+
+    try {
+        $acl = Get-Acl -Path $StoreAppsDatabase
+    }
+    catch {
+        return $false
+    }
+
+    foreach ($accessRule in @($acl.Access)) {
+        if ($accessRule.IdentityReference -eq 'Everyone' -and
+            $accessRule.AccessControlType -eq [System.Security.AccessControl.AccessControlType]::Deny -and
+            (($accessRule.FileSystemRights -band [System.Security.AccessControl.FileSystemRights]::FullControl) -ne 0)) {
+            return $true
+        }
+    }
+
+    return $false
+}
+
+function Test-StoreSearchSuggestionsDisabledForAllUsers {
+    $paths = @()
+
+    $userPathString = GetUserDirectory -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 = GetUserDirectory -userName "Default" -fileName "AppData\Local\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db" -exitIfPathNotFound $false
+    if ($defaultStoreDbPath) {
+        $paths += $defaultStoreDbPath
+    }
+
+    if ($paths.Count -eq 0) {
+        return $false
+    }
+
+    foreach ($path in $paths) {
+        if (-not (Test-StoreSearchSuggestionsDisabled -StoreAppsDatabase $path)) {
+            return $false
+        }
+    }
+
+    return $true
 }

Scripts/Features/EnableWindowsFeature.ps1

@@ -13,4 +13,37 @@ function EnableWindowsFeature {
     if ($dismResult) {
         Write-Host ($dismResult | Out-String).Trim()
     }
+}
+
+# Disables a Windows optional feature and pipes its output to the console
+function DisableWindowsFeature {
+    param (
+        [string]$FeatureName
+    )
+
+    $result = Invoke-NonBlocking -ScriptBlock {
+        param($name)
+        Disable-WindowsOptionalFeature -Online -FeatureName $name -NoRestart
+    } -ArgumentList $FeatureName
+
+    $dismResult = @($result) | Where-Object { $_ -is [Microsoft.Dism.Commands.ImageObject] }
+    if ($dismResult) {
+        Write-Host ($dismResult | Out-String).Trim()
+    }
+}
+
+function Test-WindowsOptionalFeatureEnabled {
+    param (
+        [Parameter(Mandatory)]
+        [string]$FeatureName
+    )
+
+    try {
+        $feature = Get-WindowsOptionalFeature -Online -FeatureName $FeatureName -ErrorAction Stop
+    }
+    catch {
+        return $false
+    }
+
+    return ($feature.State -eq 'Enabled')
 }

Scripts/Features/ExecuteChanges.ps1

@@ -1,3 +1,58 @@
+# List of undo actions to execute after forward changes.
+# Each entry is a PSCustomObject with FeatureId and UndoRegFile (filename, without folder prefix).
+$script:UndoRegistryKeys = @()
+
+# List of undo actions for features that do not use registry undo files.
+# Each entry is a PSCustomObject with FeatureId.
+$script:UndoFeatureActions = @()
+
+# Resolves the path of an undo reg file relative to $script:RegfilesPath.
+# Checks the Undo/ subfolder first, then falls back to the root Regfiles/ folder.
+function Resolve-UndoRegFilePath {
+    param ([string]$FileName)
+    $undoSubPath = Join-Path 'Undo' $FileName
+    if (Test-Path (Join-Path $script:RegfilesPath $undoSubPath)) {
+        return $undoSubPath
+    }
+    return $FileName
+}
+
+function Invoke-UndoFeatureAction {
+    param(
+        [Parameter(Mandatory)]
+        [string]$FeatureId
+    )
+
+    switch ($FeatureId) {
+        'DisableStoreSearchSuggestions' {
+            if ($script:Params.ContainsKey('Sysprep')) {
+                Write-Host "> Re-enabling Microsoft Store search suggestions in the start menu for all users..."
+                EnableStoreSearchSuggestionsForAllUsers
+                Write-Host ""
+                return
+            }
+
+            Write-Host "> Re-enabling Microsoft Store search suggestions for user $(GetUserName)..."
+            EnableStoreSearchSuggestions
+            Write-Host ""
+            return
+        }
+        'EnableWindowsSandbox' {
+            Write-Host "> Disabling Windows Sandbox..."
+            DisableWindowsFeature 'Containers-DisposableClientVM'
+            Write-Host ""
+            return
+        }
+        'EnableWindowsSubsystemForLinux' {
+            Write-Host "> Disabling Windows Subsystem for Linux..."
+            DisableWindowsFeature 'Microsoft-Windows-Subsystem-Linux'
+            DisableWindowsFeature 'VirtualMachinePlatform'
+            Write-Host ""
+            return
+        }
+    }
+}
+
 # Executes a single parameter/feature based on its key
 # Parameters:
 #   $paramKey - The parameter name to execute
@@ -162,8 +217,12 @@ function ExecuteAllChanges {
             break
         }
     }
+    # Undo operations that write registry values also require a backup
+    if (-not $hasRegistryBackedFeature -and $script:UndoRegistryKeys.Count -gt 0) {
+        $hasRegistryBackedFeature = $true
+    }
     
-    $totalSteps = $actionableKeys.Count
+    $totalSteps = $actionableKeys.Count + $script:UndoRegistryKeys.Count + $script:UndoFeatureActions.Count
     if ($hasRegistryBackedFeature) { $totalSteps++ }
     if ($script:Params.ContainsKey("CreateRestorePoint")) { $totalSteps++ }
     $currentStep = 0
@@ -176,7 +235,10 @@ function ExecuteAllChanges {
 
         Write-Host "> Creating registry backup..."
         try {
-            New-RegistrySettingsBackup -ActionableKeys $actionableKeys | Out-Null
+            $undoSyntheticFeatures = @($script:UndoRegistryKeys | ForEach-Object {
+                [PSCustomObject]@{ FeatureId = $_.FeatureId; RegistryKey = (Resolve-UndoRegFilePath $_.UndoRegFile) }
+            })
+            New-RegistrySettingsBackup -ActionableKeys $actionableKeys -ExtraFeatures $undoSyntheticFeatures | Out-Null
         }
         catch {
             throw "Registry backup failed before applying changes. $($_.Exception.Message)"
@@ -222,6 +284,38 @@ function ExecuteAllChanges {
         ExecuteParameter -paramKey $paramKey
     }
 
+    # Execute all undo operations
+    foreach ($undoAction in $script:UndoRegistryKeys) {
+        if ($script:CancelRequested) { return }
+
+        $undoLabel = if ($script:FeatureLabelLookup) { $script:FeatureLabelLookup[$undoAction.FeatureId] } else { $null }
+        if (-not $undoLabel) { $undoLabel = $undoAction.FeatureId }
+
+        $currentStep++
+        if ($script:ApplyProgressCallback) {
+            & $script:ApplyProgressCallback $currentStep $totalSteps "Undoing: $undoLabel"
+        }
+
+        ImportRegistryFile "> Undoing: $undoLabel" (Resolve-UndoRegFilePath $undoAction.UndoRegFile)
+    }
+
+    foreach ($undoAction in $script:UndoFeatureActions) {
+        if ($script:CancelRequested) { return }
+
+        $undoLabel = if ($script:FeatureLabelLookup) { $script:FeatureLabelLookup[$undoAction.FeatureId] } else { $null }
+        if (-not $undoLabel) { $undoLabel = $undoAction.FeatureId }
+
+        $currentStep++
+        if ($script:ApplyProgressCallback) {
+            & $script:ApplyProgressCallback $currentStep $totalSteps "Undoing: $undoLabel"
+        }
+
+        Invoke-UndoFeatureAction -FeatureId $undoAction.FeatureId
+    }
+
+    $script:UndoRegistryKeys = @()
+    $script:UndoFeatureActions = @()
+
     if ($script:RegistryImportFailures -gt 0) {
         Write-Host ""
         Write-Host "$($script:RegistryImportFailures) registry import change(s) failed. See output above for details." -ForegroundColor Yellow

Scripts/Features/GetCurrentTweakState.ps1

@@ -0,0 +1,139 @@
+# Tests whether the registry operations in a feature's .reg file currently match the live registry.
+# Returns $true if ALL operations in the apply reg file match current system state.
+# Returns $false if the feature has no RegistryKey, the file is missing, or any operation mismatches.
+function Test-FeatureApplied {
+    param (
+        [Parameter(Mandatory)]
+        [string]$FeatureId
+    )
+
+    if (-not $script:Features.ContainsKey($FeatureId)) { return $false }
+    $feature = $script:Features[$FeatureId]
+
+    switch ($FeatureId) {
+        'DisableStoreSearchSuggestions' {
+            if ($script:Params.ContainsKey('Sysprep')) {
+                return (Test-StoreSearchSuggestionsDisabledForAllUsers)
+            }
+
+            $storeDbPath = "$env:LocalAppData\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db"
+            if ($script:Params.ContainsKey('User')) {
+                $storeDbPath = GetUserDirectory -userName "$(GetUserName)" -fileName "AppData\Local\Packages\Microsoft.WindowsStore_8wekyb3d8bbwe\LocalState\store.db" -exitIfPathNotFound $false
+            }
+
+            return (Test-StoreSearchSuggestionsDisabled -StoreAppsDatabase $storeDbPath)
+        }
+        'EnableWindowsSandbox' {
+            return (Test-WindowsOptionalFeatureEnabled -FeatureName 'Containers-DisposableClientVM')
+        }
+        'EnableWindowsSubsystemForLinux' {
+            $wslEnabled = Test-WindowsOptionalFeatureEnabled -FeatureName 'Microsoft-Windows-Subsystem-Linux'
+            $vmpEnabled = Test-WindowsOptionalFeatureEnabled -FeatureName 'VirtualMachinePlatform'
+            return ($wslEnabled -and $vmpEnabled)
+        }
+    }
+
+    if (-not $feature.RegistryKey) { return $false }
+
+    $regFilePath = Join-Path $script:RegfilesPath $feature.RegistryKey
+    if (-not (Test-Path $regFilePath)) { return $false }
+
+    try {
+        $operations = @(Get-RegFileOperations -regFilePath $regFilePath)
+    }
+    catch { return $false }
+
+    if ($operations.Count -eq 0) { return $false }
+
+    foreach ($op in $operations) {
+        $parts = Split-RegistryPath -path $op.KeyPath
+        if (-not $parts) { return $false }
+
+        $rootKey = Get-RegistryRootKey -hiveName $parts.Hive
+        if (-not $rootKey) { return $false }
+
+        $key = $null
+        try {
+            $key = $rootKey.OpenSubKey($parts.SubKey, $false)
+
+            switch ($op.OperationType) {
+                'DeleteKey' {
+                    if ($null -ne $key) { return $false }
+                }
+                'DeleteValue' {
+                    if ($null -ne $key) {
+                        $names = @($key.GetValueNames())
+                        if ($names -icontains $op.ValueName) { return $false }
+                    }
+                    # key missing = value also gone = operation matches
+                }
+                'SetValue' {
+                    if ($null -eq $key) { return $false }
+                    $names = @($key.GetValueNames())
+                    if (-not ($names -icontains $op.ValueName)) { return $false }
+
+                    $actualKind = $key.GetValueKind($op.ValueName)
+                    $actualRaw  = $key.GetValue($op.ValueName, $null, [Microsoft.Win32.RegistryValueOptions]::DoNotExpandEnvironmentNames)
+
+                    $actual = switch ($actualKind) {
+                        ([Microsoft.Win32.RegistryValueKind]::DWord) {
+                            [BitConverter]::ToUInt32([BitConverter]::GetBytes([int32]$actualRaw), 0)
+                        }
+                        ([Microsoft.Win32.RegistryValueKind]::QWord) {
+                            [BitConverter]::ToUInt64([BitConverter]::GetBytes([int64]$actualRaw), 0)
+                        }
+                        ([Microsoft.Win32.RegistryValueKind]::Binary) {
+                            @($actualRaw | ForEach-Object { [int]$_ })
+                        }
+                        ([Microsoft.Win32.RegistryValueKind]::MultiString) {
+                            @($actualRaw)
+                        }
+                        default {
+                            if ($null -ne $actualRaw) { [string]$actualRaw } else { $null }
+                        }
+                    }
+
+                    $expected = $op.ValueData
+
+                    $match = if (($actual -is [array]) -and ($expected -is [array])) {
+                        (Compare-Object $actual $expected).Count -eq 0
+                    } else {
+                        $actual -eq $expected
+                    }
+
+                    if (-not $match) { return $false }
+                }
+            }
+        }
+        catch { return $false }
+        finally {
+            if ($null -ne $key) { $key.Close() }
+        }
+    }
+
+    return $true
+}
+
+# Returns the 1-based index of the UiGroup option whose features all match current system state,
+# or 0 if no option fully matches (meaning the current state is unknown / "No Change").
+function Get-CurrentGroupActiveIndex {
+    param (
+        [Parameter(Mandatory)]
+        [object]$Group
+    )
+
+    $i = 1
+    foreach ($val in $Group.Values) {
+        $allApplied = $true
+        foreach ($fid in $val.FeatureIds) {
+            if (-not (Test-FeatureApplied -FeatureId $fid)) {
+                $allApplied = $false
+                break
+            }
+        }
+        if ($allApplied) { return $i }
+        $i++
+    }
+
+    return 0
+}

Scripts/Features/RegistryBackupValidation.ps1

@@ -33,12 +33,49 @@ function Get-NormalizedSelectedFeatureIdsFromBackup {
         $errors.Add('SelectedFeatures must contain non-empty string feature IDs.')
     }
 
-    if ($selectedFeatures.Count -eq 0) {
-        $errors.Add('SelectedFeatures must contain at least one feature ID.')
+    return [PSCustomObject]@{
+        SelectedFeatures = $selectedFeatures.ToArray()
+        Errors = $errors.ToArray()
+    }
+}
+
+function Get-NormalizedSelectedUndoFeatureIdsFromBackup {
+    param(
+        [Parameter(Mandatory)]
+        $Backup
+    )
+
+    $selectedUndoFeatures = New-Object System.Collections.Generic.List[string]
+    $selectedUndoFeatureIds = New-Object 'System.Collections.Generic.HashSet[string]' ([System.StringComparer]::OrdinalIgnoreCase)
+    $errors = New-Object System.Collections.Generic.List[string]
+
+    # SelectedUndoFeatures is optional - only process if present
+    if (-not $Backup.PSObject.Properties['SelectedUndoFeatures']) {
+        return [PSCustomObject]@{
+            SelectedUndoFeatures = $selectedUndoFeatures.ToArray()
+            Errors = $errors.ToArray()
+        }
+    }
+
+    $hasInvalidSelectedUndoFeatureId = $false
+    foreach ($featureId in @($Backup.SelectedUndoFeatures)) {
+        if ($featureId -isnot [string] -or [string]::IsNullOrWhiteSpace([string]$featureId)) {
+            $hasInvalidSelectedUndoFeatureId = $true
+            continue
+        }
+
+        $normalizedFeatureId = [string]$featureId
+        if ($selectedUndoFeatureIds.Add($normalizedFeatureId)) {
+            $selectedUndoFeatures.Add($normalizedFeatureId)
+        }
+    }
+
+    if ($hasInvalidSelectedUndoFeatureId) {
+        $errors.Add('SelectedUndoFeatures must contain non-empty string feature IDs.')
     }
 
     return [PSCustomObject]@{
-        SelectedFeatures = $selectedFeatures.ToArray()
+        SelectedUndoFeatures = $selectedUndoFeatures.ToArray()
         Errors = $errors.ToArray()
     }
 }

Scripts/Features/RestoreRegistryBackup.ps1

@@ -87,7 +87,17 @@ function Normalize-RegistryBackup {
         $errors.Add([string]$selectedFeatureParseError)
     }
 
-    $allowListValidationErrors = @(Test-RegistryBackupMatchesSelectedFeatures -SelectedFeatureIds @($selectedFeatures) -Target $normalizedTarget -RegistryKeys @($normalizedKeys))
+    $selectedUndoFeatureParseResult = Get-NormalizedSelectedUndoFeatureIdsFromBackup -Backup $Backup
+    $selectedUndoFeatures = @($selectedUndoFeatureParseResult.SelectedUndoFeatures)
+    foreach ($selectedUndoFeatureParseError in @($selectedUndoFeatureParseResult.Errors)) {
+        $errors.Add([string]$selectedUndoFeatureParseError)
+    }
+
+    $allSelectedFeatures = @($selectedFeatures) + @($selectedUndoFeatures)
+    if ($allSelectedFeatures.Count -eq 0) {
+        $errors.Add('Backup must contain at least one feature ID in SelectedFeatures or SelectedUndoFeatures.')
+    }
+    $allowListValidationErrors = @(Test-RegistryBackupMatchesSelectedFeatures -SelectedFeatureIds @($allSelectedFeatures) -Target $normalizedTarget -RegistryKeys @($normalizedKeys))
     foreach ($allowListValidationError in $allowListValidationErrors) {
         $errors.Add([string]$allowListValidationError)
     }
@@ -110,6 +120,7 @@ function Normalize-RegistryBackup {
         ComputerName = [string]$Backup.ComputerName
         Target = $normalizedTarget
         SelectedFeatures = @($selectedFeatures)
+            SelectedUndoFeatures = @($selectedUndoFeatures)
         RegistryKeys = @($normalizedKeys)
     }
 }

Scripts/GUI/RestoreBackupDialogFeatureLists.ps1

@@ -82,13 +82,21 @@ function Test-RestoreDialogFeatureVisibleInOverview {
 function Get-SelectedFeatureIdsFromBackup {
     param($SelectedBackup)
 
-    return @(
-        foreach ($featureId in @($SelectedBackup.SelectedFeatures)) {
-            if (-not [string]::IsNullOrWhiteSpace([string]$featureId)) {
-                [string]$featureId
-            }
+    $featureIds = New-Object System.Collections.Generic.List[string]
+    $seenIds = New-Object 'System.Collections.Generic.HashSet[string]' ([System.StringComparer]::OrdinalIgnoreCase)
+
+    foreach ($featureId in @($SelectedBackup.SelectedFeatures) + @($SelectedBackup.SelectedUndoFeatures)) {
+        if ([string]::IsNullOrWhiteSpace([string]$featureId)) {
+            continue
         }
-    )
+
+        $normalizedId = [string]$featureId
+        if ($seenIds.Add($normalizedId)) {
+            $featureIds.Add($normalizedId)
+        }
+    }
+
+    return @($featureIds.ToArray())
 }
 
 function Get-RestoreBackupFeatureLists {

Scripts/GUI/Show-MainWindow.ps1

@@ -905,6 +905,49 @@ function Show-MainWindow {
         }
     }
 
+    # Reads current registry state and sets each tweak control to reflect whether that tweak is
+    # currently applied. Also stores the initial state on each control as a NoteProperty so the
+    # apply handler can detect which controls actually changed.
+    function LoadCurrentTweakStateIntoUI {
+        if (-not $script:UiControlMappings) { return }
+        if (-not $script:Features) { return }
+
+        $featuresJson = LoadJsonFile -filePath $script:FeaturesFilePath -expectedVersion "1.0"
+        if (-not $featuresJson) { return }
+
+        $groupMap = @{}
+        if ($featuresJson.UiGroups) {
+            foreach ($g in $featuresJson.UiGroups) {
+                $groupMap[$g.GroupId] = $g
+            }
+        }
+
+        foreach ($controlName in $script:UiControlMappings.Keys) {
+            $control = $window.FindName($controlName)
+            if (-not $control) { continue }
+            $mapping = $script:UiControlMappings[$controlName]
+
+            if ($control -is [System.Windows.Controls.CheckBox] -and $mapping.Type -eq 'feature') {
+                $applied = $false
+                try { $applied = [bool](Test-FeatureApplied -FeatureId $mapping.FeatureId) } catch {}
+                $control.IsChecked = $applied
+                Add-Member -InputObject $control -MemberType NoteProperty -Name 'InitialState' -Value $applied -Force
+                Add-Member -InputObject $control -MemberType NoteProperty -Name 'SystemState'  -Value $applied -Force
+            }
+            elseif ($control -is [System.Windows.Controls.ComboBox] -and $mapping.Type -eq 'group') {
+                $groupId = $null
+                if ($controlName -match '^Group_(.+)Combo$') { $groupId = $matches[1] }
+                $activeIndex = 0
+                if ($groupId -and $groupMap.ContainsKey($groupId)) {
+                    try { $activeIndex = Get-CurrentGroupActiveIndex -Group $groupMap[$groupId] } catch {}
+                }
+                $control.SelectedIndex = $activeIndex
+                Add-Member -InputObject $control -MemberType NoteProperty -Name 'InitialIndex' -Value $activeIndex -Force
+                Add-Member -InputObject $control -MemberType NoteProperty -Name 'SystemIndex'  -Value $activeIndex -Force
+            }
+        }
+    }
+
     # Helper function to load apps and populate the app list panel
     function script:LoadAppsWithList($listOfApps) {
         $script:MainWindowLastSelectedCheckbox = $null
@@ -1298,6 +1341,46 @@ function Show-MainWindow {
     $col0 = $window.FindName('Column0Panel')
     $col1 = $window.FindName('Column1Panel')
     $col2 = $window.FindName('Column2Panel')
+    $ShowCurrentlyAppliedTweaksCheckBox = $window.FindName('ShowCurrentlyAppliedTweaksCheckBox')
+
+    # Loads the currently applied tweaks from registry state into UI controls.
+    # When checkbox is checked: sets controls to their currently applied state
+    # When checkbox is unchecked: clears all control selections
+    function ResetTweaksToSystemState {
+        param ([bool]$loadSystemState)
+
+        if (-not $script:UiControlMappings) { return }
+
+        foreach ($controlName in $script:UiControlMappings.Keys) {
+            $control = $window.FindName($controlName)
+            if (-not $control) { continue }
+
+            if ($control -is [System.Windows.Controls.CheckBox]) {
+                if ($loadSystemState) {
+                    # Set checkbox to the currently applied state from registry
+                    $applied = if ($null -ne $control.PSObject.Properties['SystemState']) { [bool]$control.SystemState } else { $false }
+                    $control.IsChecked = $applied
+                    Add-Member -InputObject $control -MemberType NoteProperty -Name 'InitialState' -Value $applied -Force
+                } else {
+                    # Clear the checkbox
+                    $control.IsChecked = $false
+                    Add-Member -InputObject $control -MemberType NoteProperty -Name 'InitialState' -Value $false -Force
+                }
+            }
+            elseif ($control -is [System.Windows.Controls.ComboBox]) {
+                if ($loadSystemState) {
+                    # Set combobox to the currently applied state from registry
+                    $idx = if ($null -ne $control.PSObject.Properties['SystemIndex']) { [int]$control.SystemIndex } else { 0 }
+                    $control.SelectedIndex = $idx
+                    Add-Member -InputObject $control -MemberType NoteProperty -Name 'InitialIndex' -Value $idx -Force
+                } else {
+                    # Reset to first item (No Change)
+                    $control.SelectedIndex = 0
+                    Add-Member -InputObject $control -MemberType NoteProperty -Name 'InitialIndex' -Value 0 -Force
+                }
+            }
+        }
+    }
 
     function UpdateTweaksResponsiveColumns {
         if (-not $tweaksGrid -or -not $col0 -or -not $col1 -or -not $col2) { return }
@@ -1440,6 +1523,12 @@ function Show-MainWindow {
         }
     })
 
+    # Only show changed settings checkbox
+    if ($ShowCurrentlyAppliedTweaksCheckBox) {
+        $ShowCurrentlyAppliedTweaksCheckBox.Add_Checked({ ResetTweaksToSystemState -loadSystemState $true })
+        $ShowCurrentlyAppliedTweaksCheckBox.Add_Unchecked({ ResetTweaksToSystemState -loadSystemState $false })
+    }
+
     # Add Ctrl+F keyboard shortcut to focus search box on current tab
     $window.Add_KeyDown({
         param($sourceControl, $e)
@@ -1643,35 +1732,48 @@ function Show-MainWindow {
         
         UpdateAppSelectionStatus
         
-        # Collect all ComboBox/CheckBox selections from dynamically created controls
+        # Collect only controls that changed from their initial (system) state
         if ($script:UiControlMappings) {
             foreach ($mappingKey in $script:UiControlMappings.Keys) {
                 $control = $window.FindName($mappingKey)
-                $isSelected = $false
-                
-                # Check if it's a checkbox or combobox
-                if ($control -is [System.Windows.Controls.CheckBox]) {
-                    $isSelected = $control.IsChecked -eq $true
-                }
-                elseif ($control -is [System.Windows.Controls.ComboBox]) {
-                    $isSelected = $control.SelectedIndex -gt 0
-                }
-                
-                if ($control -and $isSelected) {
-                    $mapping = $script:UiControlMappings[$mappingKey]
-                    if ($mapping.Type -eq 'group') {
-                        # For combobox: SelectedIndex 0 = No Change, so subtract 1 to index into Values
-                        $selectedValue = $mapping.Values[$control.SelectedIndex - 1]
-                        foreach ($fid in $selectedValue.FeatureIds) {
-                            $label = $script:FeatureLabelLookup[$fid]
-                            if ($label) { $changesList += $label }
-                        }
-                    }
-                    elseif ($mapping.Type -eq 'feature') {
+                if (-not $control) { continue }
+                $mapping = $script:UiControlMappings[$mappingKey]
+
+                if ($control -is [System.Windows.Controls.CheckBox] -and $mapping.Type -eq 'feature') {
+                    $wasApplied   = if ($null -ne $control.PSObject.Properties['InitialState']) { [bool]$control.InitialState } else { $false }
+                    $isNowChecked = $control.IsChecked -eq $true
+
+                    if (-not $wasApplied -and $isNowChecked) {
                         $label = $script:FeatureLabelLookup[$mapping.FeatureId]
                         if (-not $label) { $label = $mapping.Label }
                         $changesList += $label
                     }
+                    elseif ($wasApplied -and -not $isNowChecked) {
+                        $label = $script:FeatureLabelLookup[$mapping.FeatureId]
+                        if (-not $label) { $label = $mapping.Label }
+                        $changesList += "Undo: $label"
+                    }
+                }
+                elseif ($control -is [System.Windows.Controls.ComboBox] -and $mapping.Type -eq 'group') {
+                    $wasIndex   = if ($null -ne $control.PSObject.Properties['InitialIndex']) { [int]$control.InitialIndex } else { 0 }
+                    $isNowIndex = $control.SelectedIndex
+
+                    if ($wasIndex -ne $isNowIndex) {
+                        if ($isNowIndex -gt 0 -and $isNowIndex -le $mapping.Values.Count) {
+                            $selectedValue = $mapping.Values[$isNowIndex - 1]
+                            foreach ($fid in $selectedValue.FeatureIds) {
+                                $label = $script:FeatureLabelLookup[$fid]
+                                if ($label) { $changesList += $label }
+                            }
+                        }
+                        elseif ($isNowIndex -eq 0 -and $wasIndex -gt 0 -and $wasIndex -le $mapping.Values.Count) {
+                            $prevValue = $mapping.Values[$wasIndex - 1]
+                            foreach ($fid in $prevValue.FeatureIds) {
+                                $label = $script:FeatureLabelLookup[$fid]
+                                if ($label) { $changesList += "Undo: $label" }
+                            }
+                        }
+                    }
                 }
             }
         }
@@ -1717,6 +1819,10 @@ function Show-MainWindow {
     # Handle Home Default Mode button - apply defaults and navigate directly to overview
     $homeDefaultModeBtn = $window.FindName('HomeDefaultModeBtn')
     $homeDefaultModeBtn.Add_Click({
+        if ($ShowCurrentlyAppliedTweaksCheckBox) {
+            $ShowCurrentlyAppliedTweaksCheckBox.IsChecked = $false
+        }
+
         # Load and apply default settings
         $defaultsJson = LoadJsonFile -filePath $script:DefaultSettingsFilePath -expectedVersion "1.0"
         if ($defaultsJson) {
@@ -1763,6 +1869,9 @@ function Show-MainWindow {
 
         Hide-Bubble -Immediate
 
+        $showAppliedTweaksMode = ($ShowCurrentlyAppliedTweaksCheckBox -and $ShowCurrentlyAppliedTweaksCheckBox.IsChecked -eq $true)
+        $selectedForwardFeatureIds = New-Object 'System.Collections.Generic.HashSet[string]' ([System.StringComparer]::OrdinalIgnoreCase)
+
         # App Removal - collect selected apps from integrated UI
         $selectedApps = @()
         foreach ($child in $appsPanel.Children) {
@@ -1771,6 +1880,7 @@ function Show-MainWindow {
             }
         }
         $selectedApps = @($selectedApps | Where-Object { $_ } | Select-Object -Unique)
+        $hasAppSelection = ($selectedApps.Count -gt 0)
         
         if ($selectedApps.Count -gt 0) {
             # Check if Microsoft Store is selected
@@ -1803,56 +1913,85 @@ function Show-MainWindow {
             }
         }
 
-        # Apply dynamic tweaks selections
+        # Apply dynamic tweaks - only controls that changed from their initial (system) state
+        $script:UndoRegistryKeys = @()
+        $script:UndoFeatureActions = @()
         if ($script:UiControlMappings) {
             foreach ($mappingKey in $script:UiControlMappings.Keys) {
                 $control = $window.FindName($mappingKey)
-                $isSelected = $false
-                $selectedIndex = 0
-                
-                # Check if it's a checkbox or combobox
-                if ($control -is [System.Windows.Controls.CheckBox]) {
-                    $isSelected = $control.IsChecked -eq $true
-                    $selectedIndex = if ($isSelected) { 1 } else { 0 }
+                if (-not $control) { continue }
+                $mapping = $script:UiControlMappings[$mappingKey]
+
+                if ($control -is [System.Windows.Controls.CheckBox] -and $mapping.Type -eq 'feature') {
+                    $wasApplied = $false
+                    if ($showAppliedTweaksMode -and $null -ne $control.PSObject.Properties['SystemState']) {
+                        $wasApplied = [bool]$control.SystemState
+                    }
+                    elseif ($null -ne $control.PSObject.Properties['InitialState']) {
+                        $wasApplied = [bool]$control.InitialState
+                    }
+                    elseif ($null -ne $control.PSObject.Properties['SystemState']) {
+                        $wasApplied = [bool]$control.SystemState
+                    }
+                    $isNowChecked = $control.IsChecked -eq $true
+
+                    if (-not $wasApplied -and $isNowChecked) {
+                        # Forward: user is applying a tweak that isn't currently active
+                        AddParameter $mapping.FeatureId
+                        $null = $selectedForwardFeatureIds.Add([string]$mapping.FeatureId)
+                    }
+                    elseif ($wasApplied -and -not $isNowChecked) {
+                        # Undo: tweak was active and user unchecked it
+                        $feature = if ($script:Features.ContainsKey($mapping.FeatureId)) { $script:Features[$mapping.FeatureId] } else { $null }
+                        if ($feature -and $feature.RegistryUndoKey) {
+                            $script:UndoRegistryKeys += [PSCustomObject]@{ FeatureId = $mapping.FeatureId; UndoRegFile = $feature.RegistryUndoKey }
+                        }
+                        elseif ($mapping.FeatureId -in @('DisableStoreSearchSuggestions', 'EnableWindowsSandbox', 'EnableWindowsSubsystemForLinux')) {
+                            $script:UndoFeatureActions += [PSCustomObject]@{ FeatureId = $mapping.FeatureId }
+                        }
+                    }
                 }
-                elseif ($control -is [System.Windows.Controls.ComboBox]) {
-                    $isSelected = $control.SelectedIndex -gt 0
-                    $selectedIndex = $control.SelectedIndex
-                }
-                
-                if ($control -and $isSelected) {
-                    $mapping = $script:UiControlMappings[$mappingKey]
-                    if ($mapping.Type -eq 'group') {
-                        if ($selectedIndex -gt 0 -and $selectedIndex -le $mapping.Values.Count) {
-                            $selectedValue = $mapping.Values[$selectedIndex - 1]
-                            foreach ($fid in $selectedValue.FeatureIds) { 
+                elseif ($control -is [System.Windows.Controls.ComboBox] -and $mapping.Type -eq 'group') {
+                    $wasIndex = 0
+                    if ($showAppliedTweaksMode -and $null -ne $control.PSObject.Properties['SystemIndex']) {
+                        $wasIndex = [int]$control.SystemIndex
+                    }
+                    elseif ($null -ne $control.PSObject.Properties['InitialIndex']) {
+                        $wasIndex = [int]$control.InitialIndex
+                    }
+                    elseif ($null -ne $control.PSObject.Properties['SystemIndex']) {
+                        $wasIndex = [int]$control.SystemIndex
+                    }
+                    $isNowIndex = $control.SelectedIndex
+
+                    if ($wasIndex -ne $isNowIndex) {
+                        if ($isNowIndex -gt 0 -and $isNowIndex -le $mapping.Values.Count) {
+                            # Apply the newly selected group option
+                            $selectedValue = $mapping.Values[$isNowIndex - 1]
+                            foreach ($fid in $selectedValue.FeatureIds) {
                                 AddParameter $fid
+                                $null = $selectedForwardFeatureIds.Add([string]$fid)
+                            }
+                        }
+                        elseif ($isNowIndex -eq 0 -and $wasIndex -gt 0 -and $wasIndex -le $mapping.Values.Count) {
+                            # Revert to 'No Change' from a detected initial state - undo the previously active option
+                            $prevValue = $mapping.Values[$wasIndex - 1]
+                            foreach ($fid in $prevValue.FeatureIds) {
+                                $feature = if ($script:Features.ContainsKey($fid)) { $script:Features[$fid] } else { $null }
+                                if ($feature -and $feature.RegistryUndoKey) {
+                                    $script:UndoRegistryKeys += [PSCustomObject]@{ FeatureId = $fid; UndoRegFile = $feature.RegistryUndoKey }
+                                }
+                                elseif ($fid -in @('DisableStoreSearchSuggestions', 'EnableWindowsSandbox', 'EnableWindowsSubsystemForLinux')) {
+                                    $script:UndoFeatureActions += [PSCustomObject]@{ FeatureId = $fid }
+                                }
                             }
                         }
                     }
-                    elseif ($mapping.Type -eq 'feature') {
-                        AddParameter $mapping.FeatureId
-                    }
                 }
             }
         }
 
-        $controlParamsCount = 0
-        foreach ($Param in $script:ControlParams) {
-            if ($script:Params.ContainsKey($Param)) {
-                $controlParamsCount++
-            }
-        }
-
-        # Check if any changes were selected
-        $totalChanges = $script:Params.Count - $controlParamsCount
-
-        # Apps parameter does not count as a change itself
-        if ($script:Params.ContainsKey('Apps')) {
-            $totalChanges = $totalChanges - 1
-        }
-
-        if ($totalChanges -eq 0) {
+        if (-not $hasAppSelection -and $selectedForwardFeatureIds.Count -eq 0 -and $script:UndoRegistryKeys.Count -eq 0 -and $script:UndoFeatureActions.Count -eq 0) {
             Show-MessageBox -Message 'No changes have been selected, please select at least one option to proceed.' -Title 'No Changes Selected' -Button 'OK' -Icon 'Information'
             return
         }
@@ -1894,6 +2033,7 @@ function Show-MainWindow {
     # Initialize UI elements on window load
     $window.Add_Loaded({
         BuildDynamicTweaks
+        LoadCurrentTweakStateIntoUI
         UpdateTweaksResponsiveColumns
         RefreshTweakPresetSources -defaultSettingsJson $defaultsJson -lastUsedSettingsJson $lastUsedSettingsJson
         RegisterTweakPresetControlStateHandlers
@@ -2224,6 +2364,10 @@ function Show-MainWindow {
     # Clear All Tweaks button
     $clearAllTweaksBtn = $window.FindName('ClearAllTweaksBtn')
     $clearAllTweaksBtn.Add_Click({
+        if ($ShowCurrentlyAppliedTweaksCheckBox -and $ShowCurrentlyAppliedTweaksCheckBox.IsChecked -eq $true) {
+            # Keep the toggle state aligned with the cleared UI selection state.
+            $ShowCurrentlyAppliedTweaksCheckBox.IsChecked = $false
+        }
         ClearTweakSelections
         UpdateTweakPresetStates
     })

Scripts/Helpers/Get-RegFileOperations.ps1

@@ -129,10 +129,13 @@ function Convert-RegValueData {
     }
 
     if ($valueData -match '^"(?<value>.*)"$') {
+        $stringValue = $matches.value
+        # Unescape registry string escape sequences
+        $stringValue = $stringValue -replace '\\\\', '\' -replace '\"', '"'
         return [PSCustomObject]@{
             OperationType = 'SetValue'
             ValueType = 'String'
-            ValueData = $matches.value
+            ValueData = $stringValue
         }
     }
 

Win11Debloat.ps1

@@ -293,6 +293,7 @@ if (-not $script:WingetInstalled -and -not $Silent) {
 . "$PSScriptRoot/Scripts/CLI/PrintHeader.ps1"
 
 # Features functions
+. "$PSScriptRoot/Scripts/Features/GetCurrentTweakState.ps1"
 . "$PSScriptRoot/Scripts/Features/ExecuteChanges.ps1"
 . "$PSScriptRoot/Scripts/Features/CreateSystemRestorePoint.ps1"
 . "$PSScriptRoot/Scripts/Features/BackupRegistryFeatureSelection.ps1"