Do you have an ATI video card? ATI doesn't make sound cards.
Even so, you can download the latest ATI drivers for your video card from
http://www.ati.com/support/driver.html
Do you use windows update? Use it from the start menu to scan for updates; there may be drivers available through Microsoft that could help with the situation.
edit: I'm assuming you have installed the driver updates through Windows update
You can use
Belarc Advisor to gather more information about your PC.