You cannot get rid of that account. It is essential for machine admin.
Boot to the hidden administrator account by booting to safe mode and choose
Administrator with no password (unless they have password protected the
account to keep you out). Once in the Administrator account, set a password
on it the same way you would any other account.
Reboot to normal mode and they will not be able to change their accounts by
logging into safe mode as Administrator with a blank password.
--
Larry Samuels Associate Expert
MS-MVP (2001-2005)
Unofficial FAQ for Windows Server 2003 at
http://pelos.us/SERVER.htm
Expert Zone-