Does your Pavilion have on-board sound or a separate sound card? If it has a separate sound card, find out what it is and go to the mfr's web site. If it on-board sound like "PC '97" go to the chipset mfr's site for sound drivers (Intel, VIA, SiS etc.). A lot of HP's mobos for AMD CPUs are made by Asus - so if it is on-board sound perhaps the drivers for a similar Asus would work. Good luck.
.bh.