Hey there, first off I have to give fair warning that I don't know a lot about the technical terms when it comes to computers, but I know enough to get my around. Anyways, as of 3 days ago, my computer started having problems where I'd be in the middle of surfing the net or playing a game, and the monitor would shut off, then right after the whole computer would freeze up. I first thought it was a overheating problem, so I got Speedfan and saw my CPU was running anywhere between 51C when it wasn't being used, to almost 70C when I had multiple programs running. So I went and bought some AS5, applied only a small even layer about the size of a grain of rice, then tried it again, but the same problem happened. So, next I tried messing w/ the power supply, thinking maybe it was the problem, and got a new 550W power supply, and still the same problem occurs. I then thought it might be the ram, but I'm not sure if that would cause it or not, or maybe it might be the video card itself. I have currently 2 512MB sticks of ram, and a Nvidia 7800 GTX video card. Sometimes the monitor won't even turn on after a hard reset, and sometimes it'll run for up to 3 hours with no problems before it shuts down, so I'm completely clueless on what to do, so any help would be greatly appreciated. Thanks in advance!