Shoutbox

You can't remove it.

Your username is Owner, I assume that this account was already created when you first got it. Using the "Change my account name" feature won't (can't) actually rename your account. It just adds the name to your account as an alias, and it shows up on the Welcome Screen and Start Menu.

If you make a new account and reallyname it Michael, then it will work how you want it, however at the moment your username is Owner with the alias Michael.

You can later delete the Owner account.