Resetting the MacOS X 10.4 (Tiger) Admin Password (without disk!)

Resetting the MacOS X Tiger administrator password can be done by booting with the Installation Disk, and selecting the appropriate menu option. This is the most commonly referred to option, with a lot of high-quality instructions available via Google.

The problem is what to do when you have no disk – or it is too inconvenient to get it. In my case, the PowerPC Mac Mini that runs MacOS X Tiger has a bad DVD drive.

In most cases, resetting a password just requires physical access to the machine and a reboot. (This is why nearly all security professionals say, If you’ve physical access to the box, it’s over.)

With Tiger, you can indeed do this. (In fact, Leopard and Snow Leopard can too – it’s just more complicated.)

Start your MacOS X 10.4 system, and at the gray screen hit (and hold) Cmd-S to enter single user mode. The screen should go black, and white writing commences – kernel messages. You should eventually get a root prompt:

#

At this prompt, type in these three commands (terminated with a return, of course):

sh /etc/rc
passwd admin
reboot

(Replace admin with your administrator user’s short username.) When I did this, I found that if you waited too long after doing the command sh /etc/rc, then the system would take away your prompt. So don’t lag!

This article (from 2009) over at MacYourself is one of the most complete descriptions I’ve seen; this 2007 article at MacOSX Tips is nearly as complete and adds some more thoughts too.

These articles saved me; I hope they can be of some use to you too.

11 thoughts on “Resetting the MacOS X 10.4 (Tiger) Admin Password (without disk!)”

  1. David,
    When I get the gray screen and press control-s nothing comes up but a blue screen and there is nowhere to type in the prompt

  2. Cher Monsieur, Merci d’avoir publié votre travail. J’ai un Emac dont je n’avais pas les mots de passe administrateur. Grâce à vous j’ai pu le modifier et à nouveau contrôler cette machine.
    Merci de la France.
    JP Lagarde

  3. can i use terminal to reset admin password? please help. i can install new softwares because of admin password. i totally forgot the admin password of my ibook G4

  4. can i use terminal to reset admin password? please help. i can not install new softwares because of admin password. i totally forgot the admin password of my ibook G4

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