There is a good chance your problem is that your graphics card is set at a too high refresh rate, start windows in safe mode and set the resolution out from your graphics card to as low as possible, normally it should be 60Hz. To get there (in XP), right click the desktop, select properties, select settings, drag the slide bar at the bottom so it displas 800 x 600 the advanced, then the monitor tab and make sure the refresh rate is set low.
Simon
July 2006