Soundcard Driver?

All-

Wondering if I could get some assistance....I have an old pc that I am trying to restore just to use as a kitchen pc and everything is working pretty good other than no sound. I went to play a sound (music) last night and error message popped up and said "no sound device installed". So I went to device manager and I see a yellow question mark but it doesn't say anything about being sound related. When I scrolled down to look at the options under the specific sound tab...all codecs and stuff are loaded and working properly?

Anyway, I looked up the model of my motherboard (AMD Athlon K7S5A) and of course I can tell from the motherboard that it has onboard sound. It states on the web that the driver for it is a "AC'97 Compliant 3D Audio Codec" or something like that. So, I guess I can try to download a new driver to see if I can get the audio working again? Is that a good first step? Additionally, I am not sure whether the onboard sound is made by Realtech or Soundmax...I got both options when I searched last night.

Any assistance would be greatly appreciated....

Thanks,
Michael