First, we need a little more information. Do you have a sound card
installed or built into the motherboard? The best way to find this is
open the Device Manager:
Windows XP -
Start - RIGHT click My Computer - Properties - Hardware tab - Device
Manager
Windows 98/ME/2000 -
Desktop - RIGHT click My Computer - Properties - Hardware tab - Device
Manager
Once the Device Manager is open, click on the plus symbol to the left
of 'Sound, Video and Game Controllers'. This will expand the listing of
devices under this topic.
Look for any yellow triangles or red triangles. These are indicators of
problems with existing installed hardware. If none of these symbols are
apaprent, then make sure you have an audio device listed. Examples
would be "realtek AC'97 Audio", "Creative Audio Device". Yours may be
something different, but these are pretty common.
If there is no audio device listed, then you have one of two problems:
1. You don't have a sound card.
2. Your sound card driver doesn't have drivers installed or has a
problem that causes Windows not to recognize it.
Once you determine which problem you have, the solutions will be
different. If you purchased your computer from a retailer and it is
under warranty, the best solution to problem 2 might be to return to
them for help. If it is out of warranty or otherwise not supported,
then reply with that situation.
If the problem is #1, then you need to install a sound card. If you are
sufficiently skilled to install new hardware, this should be easy, but
only if you are comfortable opening the computer case and installing a
card.
I am assuming you have a desktop system. For a laptop, the problem is
almost certainly a driver or hardware problem. If it is a driver
problem, reply with the make and I am sure a solution can be determined
from there.
These are the beginning steps for troubleshooting, and should help you
to determine if you are up to doing it yourself or if more experienced
help might be required.
I hope this helps.