Don't have Telegram yet? Try it now!
https://www.grouppolicy.biz/2010/03/hotfix-the-desktop-wallpaper-group-policy-setting-is-not-applied-in-windows-7-or-in-windows-server-2008-r2/
Hotfix: The "Desktop Wallpaper" Group Policy setting is not applied in Windows 7 or in Windows Server 2008 R2