System Specs:
CPU: AMD Athlon 64 X2 5200+
GPU: XFX Radeon HD 6850 1GB
Motherboard: M61PME-S2
RAM: 4GB DDR2
PSU: 880w Power Supply
OS: Windows XP SP3 and Windows 7 Ultimate duel boot partition

Problem: I recently installed a new PSU and GPU for the computer for kids to play their games, the PC belongs to my parents and is rather out-dated. After installing the new GPU it seemed to work okay, I tried stress testing with furmark and setting games to their highest graphical options. It seemed very stable and it ran everything at a very high framerate (Arma 2, Sims 3, Dragon Age 2, Skyrim etc.)

However WHILST doing non-GPU intensive activities such as browsing the web or just looking at the desktop, the computer freezes, and the screen turns to a block colour (sometimes with vertical lines). I know this usually indicates a problem with the GPU.

A few solutions I have found online and have tried include increasing the idle clock speeds from 100/150mhz (for GPU clock and MEMORY clock RESPECTIVELY) in Catalyst Control Center, to 450/800, as instructed by a person with a similar problem. This had no effect, on both Windows XP and Windows 7. Before this I had tried reinstalling and sweeping any old drivers from the computer and doing fresh installs of updated drivers to no avail.


I cannot try the GPU in another machine (as I don't have another), but are there any suggestions as to what the problem could be + possible solution?

Thanks in advance.Bump. Need help.Still have a problem, any suggestions at all?