I realise this may be blasphemy to many people, but I've never found Windows to be particularly bad at managing its drivers. In fact, I've always found it to be good. On the occasions things have gone wrong, it's tended to be me trying to "fix" something.
It does begin to seem like a hardware problem. I'd normally discount that, though, as the audio side is generally pretty robust. And the absence of an audio tab suggests drivers or hardware. So headphones in the front don't work?
In another thread you're reading, the Microsoft Fixit Center for XP is mentioned, but you're on Windows 7 I believe. Perhaps you should visit
Microsoft Fix it Solution Center, and follow the links for audio problems.