Reinstall the ATI driver. Launch Windows in Safe Mode (press F8 before Windows boots), go to Windows Add/Remove programs and uninstall everything ATI. Remove the DAO/MDAC component as well. You can use the ATI removal tool utility which can be downloaded from the ATI website. The complete set of instructions on removing ATI can be found here on the ATI website.
Go to System Devices in My Computer > Properties > Hardware, and locate the option, PCI standard PCI-to-PCI bridge. This could under other names on your PC, so contact your PC vendor if you’re unsure. Right click, and select the “update driver” option. Manually search and install the PCI standard PCI-to-PCI bridge.