It is the responsibility of each hardware vendor to install the appropriate device driver(s) into the Windows NT system. The following sections describe the installation and configuration expected for serial and NDIS WAN NIC drivers.
Installation of WAN adapters for RAS occurs in two phases:
The Remote Access configuration utility reads the Windows NT HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RAS\TAPI DEVICES registry key in order to find available ports.
Furthermore, the setup program should prevent port name contention by reading the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RAS\TAPI DEVICES registry key prior to port configuration. The setup program can then prevent the user from selecting a port name that is already in use. For example, if COM1 is already registered under the DEVICEMAP key, do not allow the user to select the name “COM1” for subsequent ports.