Instructions
Press the power button on the Xbox 360 console to turn it off. Disconnect the Wireless Networking Adapter from the Xbox 360 USB port. Press the "Xbox Guide" button on the Xbox 360 controller to turn the power back on to the console. Find "My Xbox" on the console menu.
Press the "A" button on the console controller to select "System Settings," "Network Settings," and then "Configure Network."
Press the "A" button on the controller to select "Restore to Factory Defaults" under the "Additional Settings" tab. Press the "A" button to select "Yes, restore factory defaults" to reset the Xbox 360 network settings and wireless adapter.
Press the "Xbox Guide" button on the Xbox 360 controller to turn off the Xbox 360 console. Connect the "Xbox 360 Wireless Adapter" into the USB port of the console.
Turn the Xbox 360 back on. Press the "A" button on the controller to enter "My Xbox." Press the "A" button on the controller to select "System Settings," "Network Settings," and then "Test Xbox LIVE connection." Wait for the connection message, which indicates the Xbox 360 Wireless Adapter has been returned to default settings.