This probably is something to do with corrupt sound card drivers. Is there a "speaker" icon on your taskbar? (The one in the bottom-right that you'd normally click to get volume control) If not, you'll need to reinstall your soundcard drivers.
To do that, we'll need to know what sort of sound card you have, or if you're using one that's built-in to the motherboard, what make of motherboard it is. (Typically, to tell if this is the case, a built-in motherboard one will be the one you're using if you've never put your own soundcard in)
Take a look through the discs you may have received with your PC when you bought it, look for motherboard/soundcard drivers. If you can't find any there, we'll try looking at mobo/card specs.
