*TimDaniels*
For those Googling, here are the answers:
To re-enable the modem:
rt-clk MyComputer/Manage/DeviceManager/Modems/
U.S. Robotics 56K Voics INT PnP/General tab/Device Usage
set to Enable.
Then, to silence the ring tone when a FAX arrives:
Start/Settings/ControlPanel/Printers and Faxes/Fax/Properties/
Tracking tab/Configure Sound Settings button/uncheck
"Play a sound when the line rings"
*TimDaniels*