Semi-Random Restarts

[backtoreality15]

Hello, I have an interesting situation and have come seeking advice.

My computer has worked fine since I built it a year ago (during which I've left on 24/7) and ever since last week it has started to restart intermittently. The first few times it happened I noticed it occurred during virus definition updates.

After this point, I replaced the PSU, memory and did a reformat with Windows 7.

After getting up and running again, it seems like the problem was gone and my computer worked fine for a couple days. I just now attempted installing my MIDI controller's driver and software 3 times, and in the middle of each installation attempt my computer would restart itself.

Do you guys have any idea what could be the cause of this? Any assistance would be most appreciated. Thanks!

EDIT: The whole system just froze while I was websurfing and music skipped. Had to force restart.

 

[backtoreality15]

No ideas? I feel like all it could be at this point it's the motherboard or CPU. Considering both are expensive and a hassle to replace, which one should I try first?

Thanks.

 

[cmi86]

CPU's don't really randomly go bad. I would begin to look at the board. Have you ran diagnostics on the HDD and RAM ?

 

[backtoreality15]

I did one pass of (Memtest86+) and it was fine, but I replaced it anyways since I had two duplicate sticks lying around.

I'm running a diagnostic on the harddrive right now. But would a failing harddrive cause my system to downright restart?

 

[cmi86]

I did one pass of (Memtest86+) and it was fine, but I replaced it anyways since I had two duplicate sticks lying around.

I'm running a diagnostic on the harddrive right now. But would a failing harddrive cause my system to downright restart?

Yes.

 

[backtoreality15]

Yes.

So the harddrive diagnostics just finished with a full surface scan and it passed. Should I let run Memtest86+ again on the new memory for several passes in case the slots are faulty...?