PC random restart troobleshooting.

[NeptuneUK]

The family computer will randomly restart after a minute or so but only when playing games. All other programs seem to work fine.

Its no monster:

1.8 Ghz single core AMD thing
Geforce 7600
1gb RAM


I've tried RAM, CPU and GPU stress tests but the PC seems to handle it fine, which should also rule out PSU issues.
Temperatures seem ok.
Hard drive has been changed, Ram has been alternated.

Any advice as to what should I check/try out next?

edit: I disabled computer restart on system failure in windows settings and instead of restarting, the PC freezes and unfreezes with lots of audio looping. What does this tell me? Could it be an audio issue?

 

[Tyguy]

im betting it's your graphics card. Swap it out and see what happens.

 

[No Limit]

Go to your control panel > administrative tools > even viewer. Look there for any errors at the time your computer crashes. Also, do you have a VIA chipset by any chance?

 

[NeptuneUK]

im betting it's your graphics card. Swap it out and see what happens.

I doubt it because I can run those Nvidia fancy graphics things no problem, but ill see what happens with the old 6200 just in case.

Go to your control panel > administrative tools > even viewer. Look there for any errors at the time your computer crashes. Also, do you have a VIA chipset by any chance?

Thanks I'll check that out, it's an Nvidia chipset apparently.