Lock your desktop wallpaper

Are you tired of setting your favourite picture as wallpaper everytime when others who use the pc change them? No more worry,here's a simple trick for xp users
>goto 'run'.
>type 'gpedit.msc'
>goto 'adminstrator policy'
>browse yourself and find what you can do with your computer....

you can do any thing and everything in your computer using gpedit