My sign in name not my gamertag PLEASE HELP ASAP

Everytime i sign in on xbox live the kinect recognizes me as my sister and It is because i took her gamertag and made it my own because she no longer plays xbox. How do i get the xbox to change the actual name? i tried to go into my accont info but nothing
shows up?

:)

 

Help me with a unique gamertag including the name ''Vinnie''

Some gamertag like 'Major Nelson' is just epic and unique to me. I'd like some unique gamertag with my own name 'Vinnie'.

Please help me out <3

 

Need a Gamertag Change

Hi my name is Luke. Basically I need a gamertag change but I don't have enough money to do so. My gamertag includes my last name and for some reason my friends find this funny to take the p*ss out of (idiotic friends) I dont have enough money to change my
gamertag because I spent my funds on a headset and I dont get spending money often. I just need a GT change ASAP. Please help.

Thanks.

 

You can change it at http://account.live.com