I have a two year old system that has one problem. I am running Vista 64 Bit with an ATI X1950XT graphics card. The system works great when running basic windows things and even the game Sins of a Solar Empire. But when trying to play games like Crysis, FarCry 2, World at War it only works for a while before I start seeing there visual spikes coming out of people and then the graphics driver fails and the system either freezes or restarts and I can keep going. Most of the time the computer freezes and I have to reboot. I have a 600 watt PSU so I don't think it's lack of power and I am up to date on drivers for the video card and audio portion of my motherboard. Could the card be bad? Something else? Thanks.
It's probably overheating when playing really intensive 3d games. Take it out and use a small hoover to pull dust from the fan (be careful ). You might be lucky and its still under warranty so check that out if it needs replacing.