This is a Compaq Presario V5000 with XP SP2. The modem is a Conexant AC97 Soft Data Fax Modem w/SmartCP. The HD was reformatted and all the software was re-installed using the recovery partition. The Device Manager shows everything is working with no conflicts. The modem shows it's enabled. The drivers have been updated. I've run chkdsk /r which found several "problems" but none of the "repairs" affected the modem. When I query the modem I get: "The port the modem is attached could not be opened. This may be due to a hardware conflict. Check the device manager etc." I've contacted HP tech support and they're useless.
All of this worked at one time and no hardware/software changes have been made, so to me it should still work unless the modem itself has died. But if that's the case, some kind of error (other than the one I'm getting) should show up somewhere shouldn't it?