Windows 7 Windows 7 freezes when playing video in fullscreen mode

[dozen]

Hi,

I recently finished building a new comp for the first time and have installed Win 7 64bit. Everytime I try playing a video in fullscreen mode (Windows Media Player, Youtube or VLC) , it hangs and I have to use the reset button to restart my computer.

I have an ATI RADEON 4850 graphics card, 8gb of Crucial DDR3 RAM set at 1.5v and an 850w psu. I am running Win 7 64bit. I have installed the latest Windows 7 drivers for my graphics card

Thanks!

 

[dozen]

So I have narrowed it down to flash being the culprit, DivX streams fine in fullscreen