Computer turns off while playing games

My computer had been working fine until just recently when it started to shut itself off while playing certain games . It's strange since if only does it sometimes and only on games like Cod4: MW . My first thought was maybe it was overheating but i can play Far Cry 2 for hours with no problem. Using speedfan i get these temperatures while just sitting in Windows:

Temp1 : 29C
Temp2: 87C (which i believe is my motherboard since Pc wizard reports the same temperature as my mobo)
Temp3: 39C( which is probably my Power supply since Pc wizard reports the same temp for my ps)
HDO :29C
Core:33C
CCC reports my gpu at 34C
And here are the components .

Amd 6000 125 watt verison
Gigabyte GA-MA78G-DS3H
4 gigs of Adata ddr 800
Asus 4850 512mb ( with a duorb recently installed )
Rosewill 630watt powersupply
500 gig wd hd
Vista home premium 64 bit
Xtremegamer pro soundcard

Any ideas guys ?

Download malwarebytes and run it then do a virus scan
If you don't find anything then the problem is with cod4 , i have had quite a few customers that play cod4 on pc have same problem.

It may be also a hack or virus on other players computers causing your os to shutdown make sure you have ALL updates installed.

Also try installing a good firewall and see if that fixes the problem.

Also try playing cod4 single player with the lan cable pulled out just to see.

Well 87C is pretty hot for motherboard temp if that get to hot it would cause restart, I would try other program to make sure its showing the right temp to be sure.

I had a PC that did this - bad Power Supply. A crash will give blue screen or reboot. To just completely shut off is unusual. Even with a fairly large PS like yours, you may be running close on total amp for one of the outputs. You might try blowing the PS out good with canned air. Maybe its just not getting enough air movement to keep cool.

I have had the same problem.
I removed my sound card to another PCI slot so the space between graphic card and sound card became bigger.
This caused a better air flow and no problems since.

I agree it's probably that Rosewill PSU gone bad. 87 is really high, but not enough to cause the system to shut down. That said though, I wouldnt want to see 87 anywhere in the tower! Maybe add another fan or two to the case when you replace the PSU.

Look at an Antec Earthwatts 500W, it's a good PSU that will get the job done. Or PC Power & Cooling or Corsair in the 500W - 600W range should be fine.

Good luck!

my 6000+ didnt run anywhere near that hot with the stock cooler. On stock clock it would be less than 40C all the time, and barely above 40C when it was OCd to 3.225 GHz. Now that I have a better cooler, the idles are around 27C, and full load around 35C. I gave up on the overclock and under volted the proc, so it is now running 1.05V at 3GHz. Have no system temps anywhere near 80C.

Download and run Prime95 and ATitool and run them both for 30 minutes atleast and see what happens

Other things - cut the power dust out the main stuff in the pc - video and cpu HSF's and replace the cpu hsf's thermal paste.

What sort of shut down are we talking about anyhow? Total power cut? or blank or reset? video card usually will artifact before total cut out etc but then again...