Hi I have an ATI Radeon Mobility X600 driver on XP. A few weeks ago I updated the processor driver, which was corrupt and left the processor without a driver, causing the machine's overheating cut out facility to shut down the machine abruptly several times before I spotted the problem. From the error messages I gathered during one of these shut downs, I learnt that ATI driver/operating files were corrupted.
I have resinstalled the driver several times - each time the video card works perfectly, then each time I start up I get a "Device will not start" error and the PC reverts to its onboard graphics. Then I resintall etc etc etc.
Thanks, that saves me any more time deleting and re-installing driver files, using windows scannow etc etc etc - I think you're right as I've had a similar intermittent problem with a wireless network card and ended up having to replace - it was just a bit of a coincidence that it happened when I was updating the processor driver.