Computer hangs/applications don't run after half an hour of use

[Zandareagle]

Hi all. I recently re-installed Windows 7 about a week ago because of a serious system error that System Restore couldn't fix, but now I've encountered
another problem. After about half an hour of use, my computer starts to lock up and freeze - I can move around my mouse cursor, but nothing else.
All programs stop running and basically everything gives me a "not responding" message. I can't even enter Task Manager, so I am forced to manually shutdown.

I am quite perplexed as to why this is happening since I just re-installed Windows 7 (and did a full disk format to boot) Some steps I've taken to
troubleshoot the issue are :

a) Googled for possible solutions. There are too many possible reasons why this is occuring, so I decided to post here instead.
b) Disabled all programs that run on start-up.
c) Did full anti-virus and spyware scans (I use Avast Free Edition, Malwarebytes Free Edition and Super Anti Spyware Free Edition) Nothing found.
d) Ran the /sfc scannow command with admin rights from the command prompt. No issues.
e) Did CheckDisk and System Scan on the drive with Windows 7. No issues.
f) Checked Windows Power Settings - I'm using Balanced Settings which I've had no issues with in the past.

Since it's still occuring I am getting kind of perturbed! Hopefully someone here will be able to recommend a possible solution. About the only thing I can
think about that might be causing this is a game I am running. However, I run that on the lowest possible graphical settings, and I've run it with higher
settings with no ill effects before (Final Fantasy 14 for those of you who are wondering) I also haven't installed anything new lately.

Any advice would be most appreciated!

 

[MilesAhead]

I would explorer a hardware cause. Typically freeze ups after around 20 minutes of booting are do to the component working until it heats up to normal operating temperature. Seems like every cheapie network card I bought did that. I had to remove them and go back and pay through the nose for the 3Com cards.

 

[ProstarComputer]

Can you recreate this problem under a diagnostic boot (Safe Mode with startup programs and services disabled)? If so, then I'm leaning towards a failing storage drive; perhaps even the system memory is the problem.

 

[Zandareagle]

I've managed to run a few diagnostics of my own so far, here are the results :

Astra 32 - D Drive condition "Bad" (D Drive is my alternate drive which does not have Win 7 installed)
WinDFT (Hitachi Diagnostic Utility) D Drive scan - Read Error Check (pass), Smart Self Test (Fail, Read Element Failure)

I've also managed to run Safe Mode for an hour with no issues.