Games freeze my computer

[bh2o]

So for the past couple of months my computer will start to freeze after an hour of gaming. For a while I thought it had been my video card, which I replaced and am still getting the same problems. I figured it was an overheating issue, but when I researched what normal temperatures should be, they all seemed to be okay (I will post temps below). I have no viruses, my hard drive is not corrupted and does not have bad sectors. I don't play at the highest settings either. Please send me some suggestions.

Games I play: SC2, Mass Effect, HON, CS:S, and others.

Temperatures in Celsius :
CPU: 40
MOBO: 35
SPP: 52
GPU: 37

 

[bh2o]

Here are my specs:

cpu: q9300 quad core 2.5 ghz
MoBo: EVGA nForce 750i
Case: CM Stacker 830
Mem: 8gb (4x2gb) g.skill pc2 8500
gfx: GTX 460
sound: SB Xi-Fi Xtreme
PSU: 750 watts

 

[simon12]

Those temps are idle temps you need to check the load temps while gaming, you can use HWMonitor to record the min & Max.