When you install a new modem driver, the old modem is displayed in the Dial-Up Networking (DUN) connectoid Properties.
This behavior is by design, to facilitate docking and undocking of laptops without having to re-configure settings.
If the old modem is no longer required:
1. Right-click My Network Places and press Properties.
2. Right-click your DUN connection and press Properties.
3. In the Connect using box, clear the check box next to the old modem and check the box next to the new modem.
4. Press OK.