How to reset old g4? Password blocked on OS 9.1

I have picked up an old g4 for my son to learn some basics on and I can't access anything as an administrator as it is password blocked. It is running OS 9.1. I only picked it up for 10 bucks and I'm hoping there is an easy fix?

PowerMac, Mac OS 9.1.x

Posted on Sep 21, 2014 5:53 PM

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6 replies

Sep 21, 2014 11:02 PM in response to paulbucknall

If it is a Multiple Users password, there is an easy (sort of) fix.


You will need to boot the machine to a volume (disk or drive) other than the normal hard drive. This other volume can be an external hard drive with an OS valid for that model, but is typically an install CD of appropriate version, such as one that came with the machine or a retail (white label) one of a valid OS version. A bootable utility CD, such as one for Tech Tool or Disk Warrior, is also suitable provided it uses an OS version valid for your machine.


Once you have the machine booted to this other volume/disk, open the System Folder on the hard drive. In there, locate and open the folder named Preferences. In that folder, locate the file named Multi-User Prefs. Throw that file away and empty the Trash.


Then do a normal restart, booting to the OS 9.1 on the hard drive. You should now get no request for a Multiple User password.


*****


The reason that you heed to boot the machine to a different volume is that you need to get it running using an OS other than the one requesting the password, so that the contents of the System Folder can be accessed.

Sep 22, 2014 7:13 AM in response to paulbucknall

It would have to be an earlier version.


If your 500MHz G4 is a single-processor model, it is a PowerMac G4 (AGP Graphics) model.


If it has dual processors (DP), then it is a PowerMac G4 (Gigabit Ethernet) model.


In either case the maximum OS version valid for it is OS X 10.4.11.


The minimum OS version for a retail install CD is:

AGP - 9.0 (can also use a retail 9.0.4, 9.1, or 9.2.1 CD)

Gigabit Ethernet - 9.1 (can also use a retail OS 9.2.1 CD)

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How to reset old g4? Password blocked on OS 9.1

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