OK, originally you were getting Audio Codec showing up in your BIOS and now you're getting nothing...and, you're still having problems with Win98 detecting it and trying to load drivers for it (your onboard audio.)

I would try loading the BIOS Default Settings and starting all over again. Pavilion BIOS Setup.

Also, your BIOS upgrade, version 1.10.

If you don't give up, we won't either. Keep at it!