No driver for my multimedia audio controller!

I moved my computer yesterday and now I have no sound!  Upon opening Device Manager, I see that my multimedia controller has a yellow exclamation point, but the right driver can't be found for it!  D:  My computer is a Dimension 2400 and I'm running XP, Service Pack 3.  The manufacturer for my soundcard is "UNKNOWN," since I'd rather not crack my case open to find out.  I went through an innumerable amount of posts on this comm from people with similar problems, but their solutions haven't worked for me.  Can anyone help?

Thanks SO MUCH!

Mae