PSU problem or something else?

I put everything together and installed windows, played around with it for about 4 hours then went to sleep after putting the pc in sleep mode. When i go on it this morning i was on it for about 2 hours then it shut down without any warning ect. This keeps on happening every 30mins - 2 hours!

I dont think it is due to overheating (ATI 4850 is at 50 degrees idle and cpu and case temp is around 40 degrees) so i was thinking could it be the psu or something else? Its an OCZ 600w StealthXtream PSU.

Also it seems to be working fine in safe mode. (using windows 7 RC - build 7100).

Shenty.

What are the rest of your system specifications?

Check the bios and run a scan on windows sfc/scannow from command prompt. You might also wanna check the event viewer check to see if it shows anything. The problem is this could be hardware or software and windows 7 is still in beta/rc. I know some of these options may sound off but I have seen corruption in the power settings controls and had a system shutdown or sleep randomly stuff like that randomly.

Thanks for your help everyone. Plugging it into a different socket seems to have fixed the problem! I'm running the system scan now through command prompt just to be sure. I think the problem was that the PC wasnt getting sufficiant power as the PSU cable was plugged into a 3 way socket which was plugged into a 4 way socket....And all sockets were occupied!.

Shenty.