How to Re-Install Your Modem
A common problem with modem are missing driver components for CallerID and/or
voice mail actions. One approach that can sometimes correct this situation
is a modem reinstall.
If other actions have not succeeded, try the following steps:
Steps 1-5 remove your current modem and the drivers for it. Steps 7-9 are needed so your system has booted at least once with the modem not present. Then when the modem is reinserted at Step 10, Windows will automatically add drives back to the system.
While this procedure does not always correct a modem driver issue, it many times will fix the issue. Since it takes little time and uses what you already have, it's a good thing to try before other actions.