Broken Background

I have an XP box and i cant change the backgrounds. I checked for anything hijacking it and there was nothing so what the fuck is wrong? how do i fix this?

Likely caused by a malicious program, or the remaining remnants of one. This should solve your problem:

http://www.helpmerick.com/solution_computer_cant_change_desktop_wallpaper_background.htm

Of course, be careful when modifying the registry.