Function of Modem INF Files
Modem INF files provide configuration information that is used to install modems. The modem configuration information includes:
Registry subkeys and values that are added to the Windows registry during installation.
Text strings that are displayed in a modem user interface.
A modem ID that uniquely identifies the modem.
Optional support for modem device drivers.
In many cases, registry values that are specified in the INF file are initial defaults that can be changed by the user. In some cases, multiple versions of the entries for a single modem are provided to support modem installations on multiple Windows versions. Additionally, a single INF file can be used to install multiple modem models.
The INF file includes friendly strings that are displayed in modem user interfaces, such as the modem program in Control Panel. These strings provide descriptive names for the modem and the manufacturer name.
Modem IDs identify the modem device. In Windows XP and later platforms, a modem ID must be a Plug and Play device ID. Unimodem ID's are no longer supported. For more information, see Modem ID Strings.
At one time, there was no need to provide device drivers for modems because nearly all modems supported a common command set and modem functionality was implemented in the device. Competition among manufacturers, as well as advances in technology, has led to architectures that split the feature implementation between a modem device and a Windows device driver. You can use modem INF files to install device drivers for these types of devices, which are called controllerless and softmodem devices. For more information about modem device drivers, see Adding WDM Modem Support.