Windows XP shutdown/restart/logoff don't work.

Powerpuppies

I recently moved to Colorado and since I hooked up my desktop after the move, it won't shut down, restart, or in any other way exit windows via software. If I manually turn the computer off, it dies, but when I click shutdown the icons disappear from the desktop as normal and then it just stays on my desktop wallpaper until I push the power button. Restart/logoff/switch user have no discernible effect whatsoever.