How to Designate Your Default Internet Connection in Windows Vista
It makes good sense to designate your default Internet connection in Windows Vista. Your computer uses the default connection any time you click a link to an online location or open your browser. This is great for establishing a level of security for your home computer network.
Regardless of your default connection, you can still manually open any connection by opening the Network Connections window, right-clicking any connection, and choosing Connect.
Choose Start→Network and click the Network and Sharing Center link.
The Network and Sharing Center provides links for a wide range of network features.
Click the Manage Network Connections link.
The Manage Network Connections window shows a list of each type of Internet connection that has been configured on your computer, broken down by type.
Right-click the connection you want as default and then choose Set as Default Connection.
The number (1) appears in parentheses by the connection name.