Rdeon 6850 Driver stopped working but recovered

[Chemical123]

Hello,
This error occurs when I am browsing the web or running a video. I have not even tried a video game yet, but I want smooth performance from the damned thing.
So i have encountered this error and I am at my wits end. Here is what I have tried:
-Reinstall Windows
-Checked RAM for over 16 hours, 12 passes 0 errors
-Made registry changes for Tdr delay (set it to 8)
-Reinstalled drivers multiple times, currently i rolled all the way back to 2011
-Swapped out PSU and GPU(if there are other ways to test GPU or PSU specifically via a program, please tell me)
-Switched Windows 7 theme to basic
-Made sure that when reinstalling drivers I would use driver sweeper from Guru 3d in safe mode to remove any traces of previous drivers
-Disabled onboard video card via BIOS

I just dont know what else is left.
My specs
Windows 7 64 bit ultimate
Amd Phenom II X4 955 Processor 3.21 GHZ
6 gigs of RAM DDR3
Ati Radeon 6850 HD

 

[Sakkura]

Is it a new card? The card itself might be faulty. You could try and see if it works alright in another computer.

 

[Chemical123]

The card worked for 3 years without problems, and also there are no heat issues with the PC the CPU and GPU operate well below their maximum temperatures.