If you've still not fixed it, change the screen colour depth (not size) and change it back again. Voila.
(right click on the desktop. -> Properties -> Settings tab -> Color quality. Just choose another setting. After it fixes your problem, change it back if you wish.)
Last edited by Bushfiva; 14th September 2007 at 00:54.
Reason: Added more info in case the first sentence sounds like a magic incantation