Ok here is my problem my pc has been working 100% fine with all games since i got my new video card which is a Nvidia Geforce 6800 GT. Worked with WoW perfectly and also halflife 2. Now randomly yesterday playing wow the screen turned grey and had that humming sound coming from the speakers. whole pc locked up. Now i just got Call of Duty 2 and it freezes up even more now. I was just trying to play Half Life 2 and it was working fine for about 15-20 minutes it did that thing. All drivers are up to date also. Does anyone know what this is?