Is there absolutely no way to change your Windows ID linked to your gamertag? I used my main e-mail while playing on my friends, so I used my backup email when creating my gamertag on my own Xbox 360 once I got it.. It didn't really matter, at the time, which one I used. But now that you can use messenger, I want to link my main e-mail to my gamertag, because it has all my contacts!!! The other isn't used for messaging. There's got to be a solution, otherwise there's obviously a flaw in Microsoft's plan.