I Can't hear sound on Computer, no multimedia audio controller?

First of all I am running a Windows XP 2000 Home edition OS. Okay, so I have gone to device manager and uninstalled the sound device because it had a yellow exclamation point. I rebooted my computer, and the system did detect new hardware. So I go to install that. Once the installation was complete, a window popped up saying The file vinyl97.sys on Vinyl AC97 Codec Combo WDM Disk Driver is needed. Than it says type the path where the file is located and click okay. I click okay, but nothing happens. Where would I find the path to this file? This is the driver that came up when I rebooted my computer, is it the wrong one? How do I find the right sound driver? I'm a little computer savvy, but not a technician. I just want my sound back, and every time I try something, I'm back to square one. My cousin did a re installation on my computer a while back. He had to fiddle around with the sound on my computer to get it to work after the re installation. It worked for a good while, but recently the sound isn't working and came up with No Multimedia Audio Controller. Could he have downloaded a different sound driver after the re installation or a similar one that would work temporarily with my computer? How would I trace my computer back to when the sound was working? Sorry about the long question, but please help, this is annoying.