In the "Internet Options" window, click the Connections tab.
In the Dial-up settings window, click the icon for your Internet
connection (i.e. "Gallatin River Dial-up Account" or whatever it's named).
Then click the Set Default button.
Click the radio button labeled "Always dial my default connection".
This will cause Internet Explorer, Outlook Express, and other Internet
programs to automatically connect to the Internet using the connection
you have set as the default.
Click the OK button to save the new settings.