Shoutbox

Still try finding reinstalling the drivers. Reinstalling has a habit of fixing these kinds of problems cleanly.

If you are still reluctant to do that you could try this, your computer may automatically make check-points which allow this, if not it won't work;

Start > Help & Support > Undo Changes to your computer using system restore > Restore my computer to an earlier time > And pick a date before the problem started and go from there.
I don't like the second option, because it will undo setting changes for the last few days. But your personal documents will remain safe.

I'd try reinstalling sound card drivers before resorting to this