Newly built PC crashes and shuts down at random.

[Nexoz]

Does it BSOD or give any other visual error or does it just reboot/lock up?

The only bluescreen I got was when I had the 1tb hard drive installed and I was installing windows 7 into the 500gb hard drive, it came out with an Bad_Setup_Info error. After taking out the 1tb hard drive and reinstalling Windows 7 there hasn't been a BSOD since. No visual errors either.

So yea, it just locks up and shuts down.

- Edit, every attempt on doing a hard drive test on both of the hard drives had the PC crash, the 1tb hard drive came across 17 bad sectors but they were remapped, I was told that if a hard drive had more than 5 bad sectors that hard drive was basically done for. I haven't been able to check for any errors on the 500gb hard drive cuz it seems to always crash. The highest I got to was 88% before the PC crashed on me again.

Cute signature by the way.

[SnOwBunZz]

S.M.A.R.T. directly shows the results of your HDD health, so give HDTune (or other HDD testing tools) another try to look for bad sectors.
If it's really bad sectors you'd get errors copying stuff up to the point it won't even detect in the BIOS. I know because it happened last month to me. :|

As for PSU, you'd need a PSU-tester to check for errors. I doubt it's the PSU though unless you always crash under heavy load.

edit: make sure all your cables are connected properly.