My computer worked fine. I could play all games. I didn't changed any hardware or software it just happend. 3 days ago I was playing nba live 07. Suddenly it occured that the screen froze. It was like that for about 10 seconds. And than it continued. It happed several times, and finally PC shutdown itself but I could still hear cpu working. It's just there was black screen on my monitor. And now when I play intensive 3D games it shutdown the 1st time it froze. PLease tell me what to do. I installed SpeedFan, it tells me ambient 33*C, remote1 55*C remote2 35*C HD040*C Core 27*C.
I don't know what remote1 is. But when crash occurs remote1 temperature is about 72*C. I tried to open the cover. I Put BIG fan to blow into computer.All the temperatures are low but nowthing really happend. My remote1 temp is now 52*C but still pumps up to 70*C when I'm playing games. And the crash occurs again.

What is speedfan reporting your voltages as on the +3.3v, +5v and +12v rails?

3.30v
5.03v
12.50v

The 12v rail is a little high, but I don't think that would cause system instability. See what some others say.

In the meantime, take a look at the link in my signature for random crashes and work your way through that troubleshooting guide. Hopefully you can find your problem in there somewhere!

Its a heat issue ,

Possibly PSU issue,

Remote1 is the GPU. Don't worry about 70C... most GPUs can take far in excess of 100C before thermal cutoff. Could you tell us how many A are on the 12v rail on your PSU? You need to open the case to do this. If you don't know how to find this information, take a picture of the power supply sticker and post it here, we can tell you the information.

on 12V rail is 12A.