For what i can see you have on board sound and the drivers i linked you to should do it for you.
Could you tell me the make and model of your PC? Is it say a Packard Bell and if so what model, you will find the info for this on your case some were or the paper work you got with it.
First though download these and install them
http://www.softwarepatch.com/utilities/viaac97.html