Q:

Constant crashes in windows 7 64bit when playing games

I've tried everything I can possibly think of in trying to fix this problem and I'm totally out of ideas, so any help would be appreciated:
The problem: whenever I fire up a game, it works for a short while with no problems and then it would crash.  Either its a hard crash, forcing me to reboot, or windows would report that the display driver has stopped working and recovered.  Here is a list of things I've already tried:

Drivers - tried the latest drivers (catalyst 9.12) as well as the stock drivers that came with the video card.  Also have the latest BIOS/chipset
Memtest - Ran Memtest86+ overnight, had no problems, the windows diagnostic tool also does not find any problems.
Overheating - Video card/cpu temperatures are well below peak (42 and 31 Celsius receptively)
PSU Voltage - CPUID shows that the voltage levels are all above what they should be.  The PSU itself is only roughly 16 months old and is a good model.
HDD - No errors when checked
GPU - Brand new (replaced previous card since I thought it was the problem, apparently not)
Overclocking - Everything is at stock levels, memory voltage is set to manufacturer's standard

Specs:

Motherboard: ASUS P5Q Pro
CPU: Core 2 Duo E8400 3.0 ghz
OS: Windows 7 home premium 64 bit
Memory: Mushkin Enhanced 4GB DDR2
GPU: Sapphire HD 5850 1GB
PSU: SeaSonic M12 600W ATX12V
DirectX: DX11

Event Viewer after a crash always has these logged:

A fatal hardware error has occurred.
Reported by component: Processor Core
  Error Source: Machine Check Exception
  Error Type: Bus/Interconnect Error
  Processor ID: 1
The details view of this entry
  contains further information.
A fatal hardware error has occurred.
Reported by component: Processor Core
  Error Source: Machine Check Exception
  Error Type: Bus/Interconnect Error
  Processor ID: 0
The details view of this entry
  contains further information.

A previous card that I had (4850x2) also had these errors, so I changed video cards, but the same thing is happening.

A:

A few things come to mind with the errors you've posted, the cpu may not be seated properly causing issues under full load, or windows 7 is having issues with power management because a new feature is cpu core parking.  
It's unlikely a problem with the core parking but just to be sure you can go into the power options and set everything to the maximums, (not very green but it could get the job done).
You can also re-seat the cpu, make sure you have some thermal grease on hand if you wish to go that route.
Short of that I would recommend running a bios update which can be obtained here
I included the afudos utility but you should be able to just copy the file to a usb stick and use the asus easy update from the bios itself.
The latest bios is version 2102
Edit:
I just did some further research and found 2 people that ending up correcting their issues.  One removed the x-fi pci sound card and the second disabled the on-board nic through the bios and added a usb based net card.  Both people had the same error log issues and bsod problem, unfortunately it looks like a matter of trial and error to discover the culprit.
Best of luck!

