What can I do if I forgot my administrator password?

Hello, depends on OSX version...

1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.

2. When your computer finishes starting up from the disc, choose Utilities from the Installer menu at the top of the screen. (In Mac OS X 10.4 or later, you must select your language first.)

Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access the Menubar at top.

1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.

2. When your computer finishes starting up from the disc, choose Reset Password from the Installer menu at the top of the screen. (In Mac OS X 10.4 or later, you must select your language first.)

Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Reset Password.

Reset Password 10.7, 10.8...

http://reviews.cnet.com/8301-13727_7-20087723-263/how-to-run-the-password-reset- utility-in-os-x-10.7-lion/

Then Reset your Keychain...

http://support.apple.com/kb/TS1544

You need an install disk.

You can call and order one from Apple.

Reset OS X Password Without an OS X CD...

http://theappleblog.com/2008/06/22/reset-os-x-password-without-an-os-x-cd/

Admin Hack...

http://www.hackmac.org/?q=node/4

Starts up like the first time you buy a new Mac, but after filling in all that info again, you should have access to the computer and the other Users & files will still be there... give the new User a different name than an existing one.