PC crashing while playing games but not during other heavy load

[Pixels]

For quite awhile now my pc has been shutting itself down completely when playing games. Im only playing a few games right now but it happens during all of them. They are: Crysis, Warhammer Online, Bioshock and Crysis Warhead. I thought it had to do with my graphicscard getting to warm but BFG assured me that my 8800gts should be able to handle temps over 80c and the card never became warmer than 78c in games.

Two days ago I crashed in any game after playing for just 5 minutes. So yesterday morning I decided to test out what could be wrong. I ran memtest86+ and made through 3 passes without errors before I decided that it couldn't be the RAM.

I ran RTHDRIBL for two hours in fullscreen and my graphics card was on 78c during the entire time but the pc never crashed.

I then ran Prime95 and tested my q6600 for a few hours without any errors. I tried stressing two cores at once leaving the others two unstressed and then i stressed all four at the same time without errors.

I also stressed all four cpu cores with prime 95 while running rthdribl in fullscreen mode for over 1 hour without a crash.

I googled alittle and found a thread on toms hardware with a guy with my 177.83 nvidia driver having similiar crashes in games.

It seemed sort of like the problem I was having so I uninstalled my 177.83 nvidia driver and went with 175.19 but the problem was still there.

Today the pc ran fine all day. I played crysis warhead for about an hour without anything happening and after that the computer was on for about six hours (wasnt using it all the time but I did do some photoshop work etc on it) without anything happening. Then two hours ago I ran another stress test (rthdribl + prime95 at the same time) without anything happening. I was stumped as to what could be causing this so I went to have dinner. When I got back I booted up Crysis Warhead and after about five minutes I crashed again.

Seems like it only happens at night when the pc has been on for along time.

It doesn't seem like the temps are that bad though. These were the temps I got from playing Crysis Warhead for about an hour this morning: temps after crysis

My speccs:

Windows vista x64 ultimate
q6600 (not overclocked)
4GB RAM
BFG Geforce 8800gts 512mb factory OC
Asus P5K Premium MoBo
Corsair PowerSupply 620W HX ATX


Sorry for the textwall and thanks in advance for any help!

 

[fairnooks]

Intermittent glitches can be very hard to track down. One thing it seems you haven't investigated is audio, but it could still be graphics drivers and almost anything unknown that might cause a conflict. Games are the most demanding so they find the weak links in the chain.

You might try using an optimized account just for gaming where everything else that normally runs in the background is suspended or not allowed to run and see if that makes a difference.

 

[Pixels]

Ah sound!

That I haven't tried. I just did a CHKDSK C: /F and then reinstalled crysis warhead and ran it again and it ran for about an hour before it crashed which was weird but still didnt solve the problem.

How do I test sound? Do I just have to unplug my headphones & stereo and mute the sound in the game or is it more to it than that?

edit: So I plugged out all my sound stuff and turned the sound to 0 in Crysis Warhead and It still crashed after awhile. Do I need to disable the sound in some other way or was that enough?