HELP!!!!!!!

[Gala]

I AM A NEW OWNER OF A USED COMPUTER WITH WINDOWS XP
ALREADY INSTALLED. THE PREVIOUS OWNER LEFT HIS
ADMINISTRATER PRIVILAGES INTACT!!!! GREAT FOR ME, (NOT)!
WOULD SOMEBODY PLEASE TELL ME HOW TO OVERRIDE IT CUZ I
CANT EVEN INSTALL UPDATES, MUST LESS ANY PROGRAMS OR
DELETE ANYTHING. PLEASE, PLEASE, PLEASE.....HELP ME.
THANK YOU SO MUCH!!