Things You'll Need
Instructions
Configuring Internet Connection Sharing
Open the Network Connections dialog box by clicking "Start > Control Panel > Network and Internet Connections > Network Connections."
Find the icon that corresponds to your dial-up connection. Right-click on it and select "Properties."
In the dialog that results, select the tab marked "Advanced."
Check the following boxes: "Allow other network users to connect through this computer's Internet connection" and "Establish a dial-up connection whenever a computer on my network attempts to access the Internet."
Click the button marked "OK." You may receive the following prompt:
"When Internet Connection Sharing is enabled, your LAN adapter will be set to use IP address 192.168.0.1. Your computer may lose connectivity with other computers on your network. If these other computers have static IP addresses, it is a good idea to set them to obtain their IP addresses automatically. Are you sure you want to enable Internet Connection Sharing?"
Click the button marked "Yes."
Connecting the Xbox to the Computer
Using the Ethernet cable, connect one end to the Ethernet port on the computer and connect the other end to the Xbox.
Turn on your computer.
Turn on the Xbox. The modem on the computer should begin to dial as soon as the Xbox attempts to connect to the Internet. When the connection is made, sign in to Xbox Live.