My CPU suddenly turns off, what might be the cause?

[srvida]

Hi,
I started mi PC and after several hours it turns itself off amd stays in a black mode where the only thing to do is press the on/off btn to turn it off for good.
Its an Intel pentium 4 running with Windows 7 and 1Gb Ram.
Any help please?

 

[JackNaylorPE]

Have you checked temperatures ? can it pass OCCT torture tests ?

http://www.ocbase.com/perestroika_en/index.php?Download