The original user name will always be the administrator and will always be there.  It's the root, master account.  You can add/modify attributes on it to some extent if you want, but you can't get rid of it.  You can grant, signed on as THE administrator root account, other accounts administrator privileges, but you can not make them the ROOT account.  That's pretty much locked in at initial load of the OS (as far as I know).
Bob, Still Old, Still Grey, And Still A Woolf

No trees were harmed in the sending of this message and a very large number of electrons were asked their permission to be terribly inconvenienced. And a party was thrown for them afterwards for being really cool about it.

Bob's Space - Home Page of the Olde Greywoolf

 I have bought a laptop with Vista home basic O.S last week.At first I just
 had one user that had been created with the company that I had bought my
 laptop.after it, I changed the user name to my appropriate name, but now in
 the path "C:\Users" I have two things:"Public" and my last user name that I
 had been changed it. When my user is the Administrator, why my user name
 isn't in the user folder and I have the user that I had been changed it?