I bought a G3 imac 600 from an auction. no cd's came with it. it has software on it with multiple user logins. I can only login to one user who didn't use a password but cannot login as the admin. it is running os 9.2.2 and I would like to upgrade to osx. do I first need to update teh firmware???/ if so how do I do this? will not having admin access be a problem?