BSOD's, mostly when in games

[Tomacio]

My custom built computer was working fine for about 6 months under Windows 7 64bit, and then all of a sudden it started BSOD-ing. Now it could work fine for a day or a few hours without a BSOD, but it could also get stuck in a loop of being unable to even load windows fully before BSOD-ing again.

Mostly the issue shows up when gaming, but there have been instances of BSOD's happening while staring at the desktop.

I've tried the following:

* Memtest, showed all ok.
* HDD check software, showing no bad sectors.
* Swapped RAM sticks, BSOD's remain.
* Reinstalled Win7 64bit several times. I noticed that for the first few boot-ups after a reinstall there were no BSOD's, so I convinced myself that it was in fact a Windows update that was bringing the issue. So, the last time I formatted all my drives and reinstalled Windows again, this time disabling all updates. Alas, I've had several BSOD's happen within the first 2 days.
* Removed my Audio card and fully disabled the on-board audio through Bios, thinking it may be a conflict issue - BSOD's still happen.

The issue has caused me to give up on my PC several times, but my wife's laptop simply isn't enough to cover both our daily computing needs! Can anyone help me locate the issue?

OS: Windows 7 64bit
CPU: AMD Phenom II X4 Black Edition 955
Motherboard: Asus M4A79XTD
Memory: 16 (4X4) Corsair Vengeance ver 2.12
Graphics Card: ATI Radeon 5830
Antivirus: Avast!

 

[Tomacio]

Minutes after typing the post above, I experienced another crash. This happened outside of a game. I'd like to change the title of the whole thread but can't - I don't think the issue is games related!

WhoCrashed shows me a different message for it versus the other instances:

On Wed 05/02/2014 20:33:40 GMT your computer crashed
crash dump file: C:\Windows\memory.dmp
This was probably caused by the following module: Unknown (0xFFFFF80002CD4F00)
Bugcheck code: 0x7E (0xFFFFFFFFC0000005, 0xFFFFFA800CAF9010, 0xFFFFF880037E5A28, 0xFFFFF880037E5280)
Error: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
Bug check description: This bug check indicates that a system thread generated an exception that the error handler did not catch.
A third party driver was identified as the probable root cause of this system error.
Google query: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED