installer.vm: set lock screen image

Set lock screen image to the background image used already as a
wallpaper. Use the setting fit (6) for the background image to be able
to use the same image.

packages/installer.vm/tools/chocolateyinstall.ps1

@@ -122,13 +122,18 @@ try {
         Write-Host "`t[-] %LOCALAPPDATA%\Boxstarter\boxstarter.log" -ForegroundColor Yellow
     }
 
-    # Let users know installation is complete by setting background, playing win sound, and display message box
+    # Let users know installation is complete by setting lock screen & wallpaper background, playing win sound, and display message box
     # Set background
     Set-ItemProperty 'HKCU:\Control Panel\Colors' -Name Background -Value "0 0 0" -Force | Out-Null
     $backgroundImage = "${Env:VM_COMMON_DIR}\background.png"
     if ((Test-Path $backgroundImage)) {
+        # Set lock screen image
+        New-Item "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\PersonalizationCSP" -Force | Out-Null
+        New-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\PersonalizationCSP" -Name LockScreenImagePath -PropertyType String -Value "C:\ProgramData\_VM\background.png" -Force | Out-Null
+        New-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\PersonalizationCSP" -Name LockScreenImageStatus -PropertyType DWord -Value 1 -Force | Out-Null
+        # Set desktop wallpaper image
         # Center: 0, Stretch: 2, Fit:6, Fill: 10, Span: 22
-        New-ItemProperty -Path "HKCU:\Control Panel\Desktop" -Name WallpaperStyle -PropertyType String -Value 0 -Force | Out-Null
+        New-ItemProperty -Path "HKCU:\Control Panel\Desktop" -Name WallpaperStyle -PropertyType String -Value 6 -Force | Out-Null
         New-ItemProperty -Path "HKCU:\Control Panel\Desktop" -Name TileWallpaper -PropertyType String -Value 0 -Force | Out-Null
         Add-Type -TypeDefinition @"
 using System;