trouble with admin password reset

I can't remember my admin password and after a long time of trying to remember, I decided to reset it. I restarted my computer with the first of two install discs while holding down the "C" key. I selected the language then went to the Utilities menu to "Reset Password" and selected my OSX hard drive volume. However, the only thing showing up in the drop-down menu was System Admin (root). I understand I'm supposed to select my original user name in order to change the password, and changing the System Admin wasn't allowed.

I did not actually go through and re-install both disc volumes. Do I need to do that before changing my admin password? Any ideas about what I did wrong?

Thanks in advance for the help!
Julie

You shouldn't have to reinstall the entire OS. I've never had to go through this, but from what I'm reading, it seems you should have been able to select your original user name. Here's a link with an alternate method of resetting the password.
Forgot Mac Password? How to Reset Your Mac Password (with or without CD)