The first thing to do in any situation like this is to verify whether it is a hardware or software problem. To do this boot from a from a self-contained bootable OS such as the Ultimate Boot CD for Windows
or a bootable linux distro
(with appropriate drivers included), then test the audio device to be sure that it works properly. If it works properly under the alternate software environment then most likely the problem lies with your original OS, drivers or other installed software. In that case I would first try removing and reinstalling the drivers, and if that didn't help then possibly a clean install is in order.
If the device is defective, then merely disable it and install a replacement in the form of an internal slot adapter, which in this case would be a PCI Express x1 sound card. Scott.