DSC to set Windows desktop default wallpaper bitmap
xDesktopBMPfile creates a BMP file of size, colour and text that will be used on all servers
xDesktopBackground deploys a specified file to the background via updating the 'Control Panel\Desktop' 'Wallpaper' keys for all users. In addition 'WallpaperStyle' and 'TileWallpaper' are set appropriately.