I think most of your spyware issues have been dealt with in the
other thread, but it's possible that when you removed some spyware (or something else), it may have corrupted your existing sound card driver, and the Add Hardware thing may well be a case of needing to reinstall your sound card driver from the CD. If it's a separate sound card, you should have a separate CD, but if it's on board your motherboard, the drivers should be on your motherboard CD.
As Sandra said, check in your Device Manager to see if there are any yellow symbols. If you want us to tell you where your Device Manager is, you'll have to tell us which operating system you are using (XP, ME, Win2K, Win9x, etc).