Ok, now I need to know what kind of computer it is, and it's model number. Like, a Dell dimension 123 B, or a HP 456 C.
Unless you custom built it, or installed a different operating system, then you should have a bunch of discs that came with it. Find a disc that says something like "Drivers CD" or Drivers utilities CD", or "Motherboard Drivers CD". Insert it into your CD drive (or DVD drive or whatever) and it should start automatically. Find an option that says something like "Reinstall Drivers". Click it and let it reinstall the drivers. If it lists drivers seperatly, then you'll have to find them and reinstall them seperatly. It's easier than it sounds. Sorry for all the "something like"'s, but each manufacturer is different, and will list their menu's differently.
If this doesn't work, or you don't have/can't find the CD's, then list what kind of computer it is (Dell, Compaq etc.) and the model number (dimensions xx, or a presario xx) and I'll try to find a site for you to download the drivers that you are lacking.
Be patient, we can see the light at the end of the tunnel!
War produces veterans, wounded both physically and mentally. They have sacrificed for us.....and it is now our job to help these veterans, as they have already helped us in ways we will never know, in ways that we cannot fathom, and in ways that we take granted every day.