thing is ... with security ... if you could get round it .... it wouldn't be secure .....
in XP you can't lower the profile of THE administrator
(but you have to know what the password is! - try a blank password first ... then start worrying!)
in vista ... you can't lower THE administrator ... but THE administrator is disabled by default ... and you CAN lower the priority of an "ordinary" administrator. ... and you have to have an administrator id to activate THE admin
the first two IDs created by default are admins ... so you might have a spare
failing that ... it's this ... follow the instructions carefully
http://home.eunet.no/pnordahl/ntpasswd/bootdis k.html
(if you mess up (again!!) - it's a reinstall)
the best help I can give is what I tell my muppets on their first day ... never close the door unless you have a spare key - but i suspect you know that now