2Wire Gateways are a combination of a DSL modem and a wireless router. There are many ways to configure them and many problems that can arise. There are some basic settings that should always be checked first to troubleshoot connectivity problems with 2Wire Gateways. The 2Wire Gateways also provide a wizard to help narrow down the source of problems.
Open your "Start" menu and go to the "Programs" menu. In the "Accessories" folder open the Command Prompt. In the Command Prompt, type "ipconfig" to verify you have "192.168.1" in the beginning of your IP address. If your IP address is different, you may be connecting through a third-party router or the IP address may have been manually assigned on the computer.
Open a web browser like Internet Explorer and type "gateway.2wire.net" in the address bar. This should bring up the modem's graphical user interface. If you cannot access this site, disable any firewalls you have running and reset your browser.
Click on the "Run system setup wizard" link. The system setup wizard reconfigures the modem with default settings to ensure that it is set up correctly. When prompted, enter your username and password that were created with your Internet service provider. Contact your Internet service provider with the specific error message you get if this doesn't resolve your Internet connectivity.