Instructions
Connect the Adapter
Power off the Xbox 360 and turn it around so that the rear is facing you.
Connect the Xbox 360 Wireless Networking Adapter by inserting the plastic tabs on the back of the adapter to the matching slots near the USB ports on the back of the Xbox 360.
Insert the end of the USB cable into a USB port on the Xbox 360 and then raise the antenna.
Configure the Wireless Network Settings
Turn on the Xbox 360. Go to the "System Settings" section on your dashboard and press the "A" button.
Select the "Network Settings" option and then press "A."
Select "Configure Network" and press the "A" button.
Choose "Wireless" and press the "A" button. Select the "Scan for Networks" option and press "A." Allow the console a few moments to locate your wireless router.
Select your wireless connection and press "A." This brings you to the "WEP Network" screen. Using your D-Pad, enter the network's password and press the "Start" button to save.
Press the "Guide" button. Select "Connect to Xbox Live" and press the "A" button.