While listening to Windows Media Player, my computer asks for my e-mail address and information again
Most likely your browser is set not to accept cookies. A registration program places a small cookie on your computer to track your browsing activities. Without the cookie, the program thinks you are a new user. Try adjusting your browser setting under Internet options, and the Privacy Tab. Be sure to click "apply" before exiting.
Do take note, that each time you clear your computer of cookies, you will be asked to re-register each time you want to listen to Windows Media Player.