Recently my computer wouldn't run my graphics card until I re-installed the drivers. ( It happened at every boot). At the time I was using an ATI Radeon AGP HD 2600 Pro. I had already installed the latest hot fix and so I foolishly thought it was the card. I removed it and installed an Nvidia GEForce 8400GS PCI card. At first, after having a problem installing it, ( the installation disk stated the install failed) I got it to work by getting the Add New Hardware Wizard to do it. Everything appeared to be fine including my 2 monitor set up. I wasn't satisfied with the frame rate on my Flight Sim X program but I attributed that to the PCI bus. Now about every other boot the screen resolution reverts to 800x something and I have to uninstall the card and reinstall it and then I'm back to "normal". Also, the computer locks on "standby". I have to shut it down and reboot.
Anything sound familiar to anyone??
Does your PC have an onboard IGP? if it does, I'd suggest switching to it.
Then uninstall both ATI and Nvidia Drivers and programs.
Use driver-sweeper to get rid of all remnants of the drivers and programs associated with Nvidia & ATI.
Reboot and check to see if anything from the two is left on the disc.
Shutdown, insert the Nvidia cards and boot into safe mode.
After preliminary installation of basic drivers by windows itself, boot into normal mode and install the latest Nvidia Drivers, not the ones that came with the Card.
Reboot. Adjust the resolution and then check to see if the problem reoccurs.