so I built my pc about a year ago and sometime last year, i forget how long ago, the pc froze up unexpectedly. I tried restarting it but it would not even put out a video signal when I would boot it up. So I gave up on my computer for a few months and one day had my friend come take a look at it. when he came over I had unplugged and moved my pc into another room. I turned it on to show him the non existence of a video signal and the thing booted right up.
I started using it and eventually bought a video card and windows 7 (previously had vista). I installed the video card before I put windows 7 on. This was because I was having my friend help with the upgrade to 7 so I wouldn't loose all my files by accident. so i put the new card in no problem and booted up Dragon age origins. during the first video intro the computer froze the audio stuttered then stopped and all i could do was power the system down on the tower. I tried turning it back on and i got the no video signal again. I toggled the power supply off and on then turned it on and it worked. Now when I play a game, sometimes while I'm watching a video, or while I'm testing my performance it will do this freeze up.
I tried messing with the video drivers
and nothing worked so far.
CPU AMD Phenom 9600 quad core
MB Asus M3N72-D
GPU Asus GTX560 ti