Random freezing/crashing after 1 year of perfect operation

Cyths

Honorable
Sep 1, 2012
1
0
10,510
Okay, I am experiencing a problem I'm having trouble tacking down.

Windows 7 Home Premium x64
ASRock P67 Extreme4 Gen3
Intel i5-2500k @ stock 3.3 GHz
Nvidia GeForce GTX 570
8GB RAM
128GB Crucial M4 SSD


The CPU had been OC'd to 4.7GHz for about 1 year with no problems, however I put it back to stock while trying to figure out this problem.

So my apartment has crappy wiring and semi-frequent power flickers (Yeah, I know I need a UPS). I believe one occurred overnight less than a week ago because the LED lighting on my router which I normally turn off had been turned back on and my computer had reset to a boot device not found black screen. So I looked at my BIOS and my boot order had been reset. I fixed it and started up my computer.

Here's the problems I encountered:
While playing games, using Skype, Chrome, or Windows Explorer, or probably anything else the computer would randomly freeze up. The freezes appear to be more of an application not responding situation, but instead of being able to force quit, the computer just fails to execute any operation. So sometimes I can refocus on a different window, but I'm still forced to hard reset because the computer is completely locked up. Freezes/crashes occur with a frequency of ~1/hr.

Occasionally when I restart the boot order gets reset again.

Windows Update keeps updating and installing the same two .NET updates again and again and again, even though they're listed as being successfully installed in the programs list.

What I have done so far:
Wiped SSD and did a clean reinstall of Windows
Updated BIOS
Clocked CPU back to stock
Cleared CMOS
Ran Windows Memory Diagnostic - OK
Replaced PSU

The problem still persists. I've had several more freezes similar to those experienced before. Occasionally a BSOD. Only one I was able to read before a restart was a STOP: 0x000000F. However, the Windows Update issue seems to be resolved after the reformat.

Just now updated Crucial M4 firmware and swapped RAM to other 2 bays.
Currently waiting on another crash. Will update if (when) it does.

Anyone have a clue as to what is going on here?