Modem installation problem

I want to use Windows Fax and Scan on an HP desktop computer running Win 7 Home Premium. I bought an inexpensive internal PCI fax modem and installed it, which seemed to go without problem. Device Manager reports it is working properly, but when I use the Diagnostics to query the modem I get an error that the port the modem is attached to could not be opened because of a possible hardware conflict.. The modem log reports the following:

10-16-2012 12:20:39.662 - Modem type: PCI SoftV92 Modem
10-16-2012 12:20:39.662 - Modem inf path: oem28.inf
10-16-2012 12:20:39.662 - Modem inf section: Modem3
10-16-2012 12:20:39.662 - Matching hardware ID: pci\ven_14f1&dev_2f30&subsys_205114f1
10-16-2012 12:20:39.724 - Opening the modem device failed with error 000005aa

The computer has no built-in COM ports (strictly USB), and the modem, like almost all internal modems, installs iteself on virtual port COM3. When I try to change the port to *any* other COM port, I get an error that the port has been opened by another application.

What gives here?

Anyone? Bueller???

What's the make and model of your "inexpensive PCI fax modem"? What are the minimum system requirements on that piece of hardware? Does it or is it compatible with windows 7?

Thanks for the replies. I've already tried uninstalling, shutting down and reinstalling the modem. There is no change in the behavior.

The modem is indeed Windows 7 compatible (as claimed on the box). I took out the modem and placed it an another computer running Windows 7 Ultimate. It recognized the modem, installed the driver and ran the diagnostics without any problem whatsoever. Unfortunately that's not the computer I need to use with Windows Fax and Scan.

I'm now focusing on why the HP desktop claims *all* (every single one) COM ports are in use.

I've posted this question on four different forums, and the few replies I've received admit that the authors are as perplexed as I am.