Well, I had the same problem with my Compaq Presario 5000 A Series PC with no
sound. It has a sound card installed in it. The problem with no sound was the
drivers. It was working fine 3 months ago when I last used it, but now that I
rehooked it up there was no sound. It turns out as soon as I removed the
sound card I saw the three prong jumper on the motherboard that was hidden
from view because of the sound card. I looked and saw it was enabled. OH!
That's it! As soon as I moved the jumper from the 1 & 2 prongs to the 2 & 3
prongs and booted it, the familiar sound of Windows XP sounded. Eureka! When
I disabled the onboard sound the system found the drivers for the sound card.
All this time, 5 years, the onboard sound has been enabled because the jumper
was on the 1 & 2 prongs, enabled, instead of the 2 & 3 prongs, disabled.
I hope that helped you or someone out a bit.
Thanks, attilathehun1