Dos you have the System Install Disk?
yes. I have already used the instructions on the install disc. It keeps asking me for my old password, and I cannot remember it.
You only need the admin username not the password:
who is that?
or what is that?
Resetting the original administrator account passwordFollow these steps to reset a password XXXXX there is only one administrator account on the computer, or if the original administrator account needs a password XXXXX "Original" administrator account refers to the one that was created immediately after installing Mac OS X. If the original administrator password XXXXX XXXXX that administrator account may be used to reset the passwords of other administrator accounts using the steps described above. These steps require an optical drive; if your Mac does not have an optical drive and you have a Mac OS X v10.6 Install disc, see below.Start up from a Mac OS X Install disc (one whose version is closest to the version of Mac OS X installed). Usually, you can start from the disc by putting it in your computer, restarting, and holding the C key. Or, put it in the computer and click the Install or Restore icon you see in the disc's main window (after which the computer will start from the disc without you needing to hold C). Or, you can use Startup Manager or the Startup Disk preference pane to select the Install disc. Choose a language, click the arrow button to continue,Mac OS X v10.6 or later: Choose Password XXXXX from the Utilities menu.Mac OS X v10.5 or v10.4: Choose Reset Password XXXXX the Utilities menu.Mac OS X v10.3: Choose Reset Password XXXXX the Installer menu.Tip: If you don't see this menu or menu choice, you're probably not started from the disc yet. Note: The default keyboard layout is U.S. English while started from the installation disc. If you use a keyboard layout other than U.S English, use the Input menu (the flag icon on the right side of the menu bar) to select the desired layout before typing a new password. Select your Mac OS X hard disk volume.Select the user name of your original administrator account.Important: Do not select "System Administrator (root)". This is actually the root user. You should not confuse it with a normal administrator account.