Where do I find my original administrator password

Resetting or changing a password:

For Snow Leopard or earlier: http://support.apple.com/kb/HT1274

For Lion or later: http://support.apple.com/kb/HT6022

This is also useful:

http://www.macworld.co.uk/ipad-iphone/news/?newsid=3463233&olo=email

If it's running Mac OS X 10.6.8 or earlier, insert a Mac OS X install DVD, restart with the Option key held down, click on it, and use the Reset Password utility.

If it's running Mac OS X 10.7 or newer, restart with the Command and R keys held down, open the Terminal, and use the resetpassword command:

https://discussions.apple.com/docs/DOC-4101

How old is your Mac/which model?

If it came with an OS earlier than Lion and the firmware was not updated (or does not meet the minimum requirements to do so), then Command + R will not work.

You need to follow Klaus1's other instructions: insert the install disk and start up with Option key held down (see instructions above).

Thanks - we cross-posted.......