Hello.
There are two kind of sound devices that can be inside a
pc:
- Integrated on board ( in your
motherboard).
-
Sound card ( a card that is plugged in one of the motherboard slots).
If you have any installed, you will need to install a
software called " Sound driver " for that specific device, in order to make it work.
you can find the software in one of the CDs you get usually with the computer when you buy it.
If you don't have that CD, to find that driver you need to know the kind, model and manufacturer of that device, if you have the integrated one, you should visit the motherboard manufacturer
website.
For the card go to the card manufacturer website or do a google search, there are sites where you can get the drivers(the last applies for the motherboard too.)
Hope this help you.