Quote Originally Posted by rik
ok...first thing that comes to mind is an old joke that people tend to play on each other. Take a screenshot of the desktop, set that as the background wallpaper and then set Windows to hide the icons. Are you sure there aren't any jokesters around?
Hehe... thats pretty funny, and one to remember

On topic, I've had a similar problem, i think it was due to corrupt chipset driver, the IDE and I/O controller drivers got mixed up somehow