Bypassing Group Policy to set wallpaper with powershell.

Some Group Policies will force you to use a specific wallpaper. You can use this script to change your wallpaper.

You first want to start by creating a file named wp.ps1 with you favorite text editor.

wp.ps1

                               
Add-Type @"
using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;
namespace Wallpaper
{
   public enum Style : int
   {
       Tile, Center, Stretch, NoChange
   }
   public class Setter {
      public const int SetDesktopWallpaper = 20;
      public const int UpdateIniFile = 0x01;
      public const int SendWinIniChange = 0x02;
      [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
      private static extern int SystemParametersInfo (int uAction, int uParam, string lpvParam, int fuWinIni);
      public static void SetWallpaper ( string path, Wallpaper.Style style ) {
         SystemParametersInfo( SetDesktopWallpaper, 0, path, UpdateIniFile | SendWinIniChange );
         RegistryKey key = Registry.CurrentUser.OpenSubKey("Control Panel\\Desktop", true);
         switch( style )
         {
            case Style.Stretch :
               key.SetValue(@"WallpaperStyle", "2") ; 
               key.SetValue(@"TileWallpaper", "0") ;
               break;
            case Style.Center :
               key.SetValue(@"WallpaperStyle", "1") ; 
               key.SetValue(@"TileWallpaper", "0") ; 
               break;
            case Style.Tile :
               key.SetValue(@"WallpaperStyle", "1") ; 
               key.SetValue(@"TileWallpaper", "1") ;
               break;
            case Style.NoChange :
               break;
         }
         key.Close();
      }
   }
}
"@
[Wallpaper.Setter]::SetWallpaper( 'C:\Users\ %username%\Documents\start\Penguins.jpg', 0 )

Be sure to change "C:\Users\ %username%\Documents\start\Penguins.jpg" to the location of your image

Now that you have the powershell script ready. You can create a ".bat" file to run it.

start.bat

```
powershell.exe -executionpolicy remotesigned -File  C:\Users\ %username%\Documents\start\wp.ps1
```
Be sure to place everything in the correct file locations and these scripts should run properly.

*NOTE* This will only change your wallpaper while you are logged in. If you want your wallpaper to be changed everytime you login you need to create a shortcut and add it to your startup folder.