Potential,
Another approach is to install a fully hardware based dial-up modem. That
is, a modem with on-board controller and DSP (Digital Signal Processor).
Fully hardware based modems require no drivers, apart from those Windows
applies to make the modem fully functional. Just install it and boot.
Windows takes care of the rest. If you use any software with such a modem,
such as a FAX application or a call waiting feature, then that software must
be Vista compatible.
The U.S. Robotics Performance Pro is such a hardware modem, and costs about
$70, give or take a few depending on the deal you find. Other hardware based
brands are also available, including the Zoom brand. These modems cost more
than a software based modems, where the Controller and DSP functions are
performed by software. That's where the compatibility problem come into the
picture.