Fix Modem Unknown Response

If your modem is receiving caller ID information (as determined by the modem log test), but Audio Caller ID is not reporting caller ID information, then your modem driver is the problem.  This is usually easily fixed.  You can either fix the modem driver, and re-install it, or you can directly edit the list of known responses in the Windows registry.  The following instructions explain how to edit the list of known responses for your modem.

First, follow the steps outlined to obtain your modem's call log for an incoming call.

If your modem is receiving caller ID information you will find DATE, TIME, NMBR, and NAME strings in your call log, but they won't be understood by Windows.  An example of this is shown here:

Notice that after receiving the caller ID information, this was interpreted as an "Unknown Response".  To fix this, we will modify your modem's known responses in the Windows registry.  We need to add a known response for DATE, TIME, NAME, and NMBR.  (If your call log shows DDN instead of NMBR, use that instead.)  Open up the regedit program and browse to the registry key:

HKEY_LOCAL_MACHINE
  SOFTWARE
    Microsoft
      Windows
        CurrentVersion
          Unimodem
            DeviceSpecific
              <your modem>
                Responses

From within this registry key add all of these binary values:

Notice for each for DATE, TIME, NAME, and NMBR. there is a version with "=" after it, and also one with " = " after it.  The second one has a space before and after the equal sign.  The first has no spaces.

After making these changes, re-start your computer and repeat the modem log test.  The modem log should no longer show "Unknown Response", and Audio Caller ID will start displaying the caller ID information.