Video Drivers Not Responding

[Jack-o]

I bought a Radeon HD 6850 a few months back and it runs fine normally, but one day I decided to fiddle with the fan speeds to try and lower my card temp a bit, so I enabled the Graphics Over Drive option in the AMD Vision Engine Control Center and then enabled manual fan speeds. I tweaked a few of the speeds, decided I would only turn them up before starting to play a game, turned off the over drive settings (no clock speeds for either memory of GPU have been altered from defaults). The next time I turned on over drive and turned on manual fan control, my computer freezes for a minute and then screen goes black and comes back up and says the graphics drivers have stopped responding. Now any time I turn on the over drive settings and apply then (not even turning on manual fan control), the drivers stop responding. I have triple check and made sure all default values are set for all clock speeds and it still stops responding. I have also tried LOWERING the clock speeds and doing over drive, and still drivers stop responding. However, if I just leave the over drive settings off, the drivers have never stopped responding.

System Specs:
Processor: AMD Phenom II X4 955 3.2GHz Quad-core
Memory:4GB RAM
Hard Drive:1TB
Video Card: AMD Radeon HD 6850
Monitor:HP 2009m
OS: Windows 7 Home Premium 64bit
Motherboard: ASUS M4N68T-M V2
500W PSU

 

[JackNaylorPE]

Uninstall the drivers
Use a reg cleaner to remove all things related to ATI/AMD video
Reboot
Reinstall drivers from a fresh d/l manually....dont let windows do it for you.