Computer just restarts during Gaming

[frenchy_thekid]

I built this computer and here are the specs...

- AMD athlon II x2 255 processor 3.1 GHz
- Memory: 4096MB RAM
- DirectX Version: DirectX 9.0c (4.09.0000.090)
- Windows XP Professional x64 Edition
- Nvidia Geforce GTX 260 w/750 PSU

Here is my issue,

I have been playing games no problem. I had to reinstall XP and first time playing a game. Starting playing using steam. After about 15 min the game either freezes and starts "clicking" or my screen goes out and my computer restarts. It is not a heat issue, I recently due to memory issues switched over to DDR2 memory 8GB. Once the computer restarts No issues doing normal day-to-day use of computer only when I play games. Graphics card has been updated to latest version

- Could it be damaged
? - memory issues?

 

[RealBeast]

I would run MEMTEST86 to be sure about the memory.

 

[Hawkeye22]

Shutdown during gaming is almost always heat, memory, or PSU. Run memtest86 as advised. Use HWMonitor or some other tool to check temps. Make sure your PSU is rated properly for your video card and system. You didn't list your PSU in the specs.

 

[frenchy_thekid]

the PSU is 750 watt. I will check my memory i have been playing the game for a few minutes and my core temp hasnt gone above 23*.

 

[frenchy_thekid]

I ran Memtest 86 from my diagnostic tools CD and it has over 73000 errors, does that mean that the memory is bad?

 

[RealBeast]

I ran Memtest 86 from my diagnostic tools CD and it has over 73000 errors, does that mean that the memory is bad?

Yes, it should have no errors if the memory is good.