Things You'll Need
Instructions
Turn on your Xbox 360, but do not sign in to your Xbox Live account if you have one set up.
Press the large button located in the center of your controller.
Highlight ̶0;Recover Gamertag,̶1; then press the ̶0;X̶1; button.
Select ̶0;Recover Gamertag,̶1; then enter your Windows Live ID and password.
Choose the option to port your Windows Live ID to your Xbox 360.