Things You'll Need
Instructions
Internet Connection Sharing method
Open the Start menu, click on the "Run" button, type "ncpa.cpl" into the text box, and then hit "Enter" or click "OK." In Windows 7/Vista, you can type this in the search box at the bottom left of the Start menu instead.
Right-click on the Internet-connected network connection, select "Properties" from the context menu, and then open the "Advanced" tab. In Windows 7/Vista, select the "Sharing" tab.
Click to check the check-box next to "Allow other network users to connect through this computer's Internet connection," and then save your settings by clicking "OK."
Insert your Ethernet cable in the network port on your secondary network card, and then insert the other side into the network port on your Xbox 360.
Turn on your Xbox 360 and test your Xbox Live connection. Open the "My Xbox" menu, press "System Settings," choose "Network Settings," press "Wired Connection" (if prompted), and then select the "Test Xbox LIVE Connection" button. If it tells you that it is not connected, reset your Xbox 360 network settings by going to the "Additional Settings" section inside "Network Settings" and choosing "Restore to Factory defaults."
Network bridge method
Open the Start menu, select "Run," type "ncpa.cpl" in the text box, and then press "Enter" or click "OK." In Windows 7/Vista, type this in the search box on the bottom-left side of the Start menu.
Click on your primary, Internet-connected network connection to select it, press and hold the "Ctrl" key on your keyboard, and then click on your secondary connection to select it.
Right-click on one of the two connections, and then select the "Bridge Connections" option. When the connections are bridged and ready for use, a new icon will appear in the folder called "Network Bridge." Finish connecting your Xbox 360 to your Windows XP laptop by reading steps four and five of the "Internet Connection Sharing method" section.