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Unimodem and RAS

Windows NT 4.0 Remote Access Service (RAS) includes support for Unimodem modems. Most modems conform to the Unimodem standard, but if you have an older modem that doesn't seem to use RAS correctly, it may be because the modem's not supported by Unimodem. If that's the case, you'll need to configure RAS to use the Modem.inf file instead of using Unimodem.

Here's the registry edit that will allow you to use Modem.inf:

1. Using Regedt32, navigate to the following subkey:
   HKEY_LOCAL_MACHINE\Software\Microsoft\RAS\
2. Add these values:
   Value Name: EnableUnimodem
   Data Type: REG_DWORD
   Value: 0
3. Restart NT, then after the reboot go to the Network icon in the Control Panel and choose the Services tab.
4. Select Remote Access Service from the list of installed services and click the Properties button.
5. Remove any ports currently defined in the RAS Setup dialog box.
6. Click the Add button and re-add the ports. RAS will now use the Modem.inf file to retrieve initialization information for the devices you add.

Note: Please remember that editing your registry can be risky, so be sure you have a verified backup before you begin.