Things You'll Need
Instructions
Install PdaNet both on your phone and computer. Connect your computer to your phone using a USB cord.
Connect your computer to your phone's internet connection using PdaNet by opening it and running it on your phone, then opening it on your computer and selecting "Connect."
Enable Internet sharing by clicking "Start", clicking "Control Panel", then double-clicking "Network Connections."
Go to the Advanced tab, check "Allow other network users to connect through this computer's Internet connection" box. Open the "Home networking connection" and select "Internet Connection Sharing". Choose the PdaNet connection that you are using on the computer that the Xbox will be connecting to.