Odd problem when playing CoD4 and CSS

When I play call of duty 4 and counterstrike source, after ive been playing for about 5-10 minutes, my computer will flash something that looks like blue screen of death, and then restart. I can play bioshock and crysis maxed out for hours straight without this problem, it only happens in these games.

So far i've tried this:
reinstalling the games multiple times (i even used a different disc once)
messing with the graphics settings on games

PLEASE anybody who has an idea of what might be happening let me know.

Nothing is overclocked as of now
3.0ghz dual core processor
nvidia 8800gt vid card
p5n-e mobo
2gigs of ddr2 800
windows XP is my OS
mostly i run like AIM and xfire in the backround, maybe a mozilla or 2

see i dont think it would be a hardware issue because other games run flawlessly, i get 60+ fps in bioshock and 40+ in crysis on high...

i used my mobo driver discs that came with, and my vid driver is up to date

ill completely uninstall it and see what happens, was the crashing your whole PC or just the game? cause my computer completely restarts

well it just freezes for like 1 second, makes some odd noise, flashes BSOD, then reboots

I Suppose if you are really desperate you could try reformatting....

I have the same problem, Almost same spec

3.0ghz Quad core
Nvidia 9800gt
4ghz Ram

I have tried formatting and reinstalling windows 3 times now. Same issue over and over again.

When playing COD4, Rogue Spear, R6 Vegas, it plays fine for a little while like it should on this system. Then 30 mins or so later the crashes begin. The crashes on rogue spear go like this.. it'll halt the game and u'll hear the sound looping (usually someone has talked on vent during the crash and i just get their first words repeated over and over again. Sometimes i manage to get back into windows and it seems to be all good, untill i try relaunch the same game again and i have to reboot due to the same problem but this time as soon as i get into the game. After a restart it'll play for a further 10-15 mins then crash again in the same fashion and i'll have to do a finger push reboot.

CoD4 is a little more dramatic. It does the same thing as Rogue spear but it wont get back into windows i'll have to do a finger push reboot.

I've been through hundreds and hundreds of forums looking for someone with this exact same problem, although i have found hundreds with the same problem, none have given any way to fix this problem, and formatting /reinstalling windows hasnt helped at all.

Any idea's guys?