set regadd=reg add "HKEY_CURRENT_USER\Control Panel\Desktop" %regadd%" /v TileWallpaper /d "0" /f %regadd%" /v Wallpaper /d "你需要换的背景图片地址" /f %regadd%" /v WallpaperStyle /d "3" /f RunDll32.exe USER32.DLL,UpdatePerUserSystemParameters