PC turns off after a few minutes of launching a game, whats the problem?

I've had my PC from MESH, running VISTA for 2 years now and everything works fine under normal load / tasks such as office, outlook, internet browsing etc. However, when I'm playing games - any games at that, within a few minutes the PC will just turn off - completely dead. Powers back on fine but there are no errors reported in the Windows Event Log. This has only started happening recently, approx. last 3 months.

The only changes I have made to the PC in this time are Windows Updates and Nvida Graphics card driver updates. I have rolled back the graphics card drivers to see if this was the problem but the fault still happened so I don’t think it is a driver issue. I have since gone back to the latest drivers.

I can only assume that when playing games, the CPU is working harder so it is a CPU, power or heat problem? Does any one else have the same issue - and how did they fix it?

Any help or advice would be really helpful as going mad now! :-(
Mark

Sounds like it's overheating. Open up the case and see if it's clogged up with dust.

Post closed - repeated in Technical and advisory.