Windows Live ID (Formerly known as Passport) is a single sign-on service offered by Microsoft. Setting up a Windows Live ID allows you to access several different applications with the same credentials. Some applications that use your Windows Live ID to authenticate you include Hotmail, Windows Live Messenger, and MSN. Xbox Live also uses your Windows Live ID! If there were no Windows Live ID service in place, you would need a separate ID and Password to access each of these services.
Do you mean a Windows Live ID?
Yes.
Free
well im not sure if your could but if you could please help me too
No
No u cant
You cant :P
yes but it costs 800 Microsoft points
U have to contact xbox live support
Unfortunately you cannot change your windows live id. If you get it wrong or want to change it you need to create a new account with accurate details.
Sign out of Live Mesenger, then sign in with the correct account~