How to delete "other" user account

earlier today my macbook air kind of froze up and i called apple for help. They had me make a new account called root which is a system administrator or something. After having to reinstall Lion in the end, now instead of only having the option to log in to my account that i use, it has the option of that account and an account called "other" where you click on it then type in the name and password. I don't really want those two options, i just want mine. I went into system preferences and then users and tried to delete it, but it won't let me click on it. then i logged into the "root" one and went to it, i clicked on it, but it wouldn't let me click the - button to delete it.

Does anyone know how to get rid of this account?