Checking "Remember my User Name on this computer" will save your user name on the computer you are using so that you don't have to retype it every time you log in.

To turn off this feature, just uncheck the box, and your user name will not appear the next time you log in.

Note: When you save your user name, it's stored on the computer you are using; therefore, you should never save your user ID on a public computer, such as in a library or airport.