Animation Background

How can you get an animation as your background without downloading anything?

I NEED HELP! (do you need to save the pic in a weird where)
I have tried saving this animation (http://s198.photobucket.com/albums/aa316/p_rod_4/?action=view&current=behappy.gif) as a gif and a bmp on my pictures then i go to properies on the desktop and i set it as my background but it won’t move (it gets the first frame)

You need to download animated desktop themes

Where to get good animated backgrounds for FREE! (Useful for Chroma Key, and all other media!)