Avoiding ID Problems When Upgrading a Modem
WHQL standards require that upgradeable modems have hardware ID strings that can be updated.
The following problems might occur during a modem upgrade if the modem's hardware ID cannot be updated:
The upgraded modem might not be automatically detected as a new device. Remove the old modem installation (for example, registry entries and unused files) during your upgrade process to avoid this problem.
The new INF file might contain a hardware ID that duplicates the hardware ID used in the old INF file. In this case, see How Setup Selects Drivers to see how INF files and drivers are chosen for installation.
If the user upgrades to (or reinstalls) Windows XP or a later version, then the upgraded modem will be detected and automatically reinstalled at system startup time. If the hardware ID was not changed after a modem firmware upgrade, the operating system will use the old (and possibly incorrect) INF file to install the old drivers.