Which card? Don't use the drivers that come with the driver CD, they are usually very old. Download them from the GPU manufacturers website.http://www.nvidia.com/page/drivers.html
- For Nvidia cardshttp://ati.amd.com/support/driver.html
- For ATI (now AMD) cards
Make sure you go to Add/Remove Programs and uninstall the old drivers first, then reboot, install the new ones, reboot, hope it works.