Computer freezes when playing games!

Hi guys i have a little problem when ever i play a game after 10min and up to 2 hours my computer will lock up. What happens is ill be playing a game like WoW or lineage 2 and the screen distorts really bad or the screen will just go black. It locks up my computer and i have to manually restart the computer each time this happens and it only happens when im playing a game. I have updated all my video drivers windows updates things like that. I have also ran stress tests on my Video card but everything seems fine with those tests i am at a complete loss as to whats happening. the comp is about 3 months old and this started about a month ago and its getting more frequent. If anyone has any ideas or has run into this problem before any help would be greatly appreciated. Thanks


Specs:
Amd phenom x4 2.3ghz
Gigabyte AMD 769 HDMI MB
Nvidia GeForce 9800 GTX+ 512mb 256-bit
G.SKILL 4gb(2 x 2gb) ram
Windows 7 OS
WD 160gb HD

 

Any Strange noises? Like unusually loud fans?

Did you contact the People you Bought it off?

Could be over heating, What kind of case is it in?

 

Sounds like a Graphics card overheat issue but have also seen this caused by a Faulty 12v rail on the PSU. Check that the fan for your GPU is not mucked up with dust.