Modem Upgrade Example
To upgrade a modem that operates at 33.6 Kbps (V.34), the modem manufacturer distributes a software or firmware upgrade that supports 56 Kbps (V.90) operation.
The modem's INF file must be upgraded to enable these new features. For example, new support commands that enable 56 Kbps and new responses, such as CONNECT messages, must be added to the modem INF file.
The upgrade requires the assignment of a new hardware ID to the modem. If the INF file has been updated but the modem hardware ID has not been changed, Windows will not detect the firmware change and will not install the updated INF file.
The upgrade process of the modem manufacturer performs the following actions:
Writes a new INF file to the system. The hardware ID in the INF file must match the new modem hardware ID.
Downloads the new modem firmware into the modem.
Modifies the hardware ID, using either the PC-based upgrade software or the modem firmware.
Cleans up any unused files or remaining registry entries from a previous installation.