Faxing from Win2K - OK on one PC, not on the other

Hi All,

We need to fax from PC #2 but faxing only works from PC #1. Both PCs run
Win2K with SP4 and I can't find what's different.

Using an external fax modem and the Win2k fax service and fax queue on PC
#1, faxes are sent successfully, either by File/Print to the fax queue with
the wizard, or from Outlook.

Using the same modem and phone line on PC #2 and the identical software
setup and process, sending faxes fails every time. The modem dials, the fax
machine answers, then after about 15-20 seconds the connection drops with a
transmission error. It appears that the fax modem and fax machine's modem
can't get start up communication - but only when PC #2 is used.

I have compared versions of all exe's, .dll's and drivers that I could
identify that might be implicated, hoping that an old file was sitting
somewhere it shouldn't be, but no differences were found. (This doesn't mean
I have checked all the right files of course!).

Also the modem works fine on both PCs for non-fax use.

The modem properties in Control Panel / Phone and Modem Options / Advanced /
General are identical on both machines (57600 / Sandard EC / Compression
enabled / Hardware flow control).

Any suggestions on what to try or check will be very much appreciated.

Cheers,
Scott