The model number of my HP ze5170 is F4680H.
I have re-installed the drivers for the "hp omnibook XE4400-KD series Driver Package for Window XP" found at
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for the sound device and the modem. Specifically, Conexant AC-Link Audio driver v6.13.10.8080 and Conexant 56k ACLink Modem driver v5.03.09.
Incidentally, I recently (subsequent to the above) replaced the non-functioning CD ROM with "F4640-60934 CD-ROM drive - 24X-max speed" and repaired the broken AC jack on the motherboard.
All is well but for no sound, no modem.