Have you tried going back via control panel.system.hardware etc, to where the item is shown - check properties and click on update driver tab - firstly when it asks you for driver just go to C;Windows /system and see if it finds anything - failing that theres a driver here
http://www.opendrivers.com/driver/216818/c-med ia-cmi9880(azalia)-ac97-codec-driver-5.12.01.0 007-windows-98se-me-2000-xp-free-download.html
which yuo could download and do the same thing but just instal from wherever you save this download.
Having googled the problem, it doesnt sound unique, quite a few people seem to have this problem with this sound card