Factory reset an iMac G3 without a disk?

Yes, provided the machine is running some version of OS 9, but you will need to use a bootable CD. This CD need not be an OS Install CD; it can be a utility CD, such as Disk Warrior or Tech Tool. You just need to be able to boot the machine to an OS not resident on the hard drive.

Once booted to the CD, do not run any install program, etc. Then open the System Folder on the hard drive; in that folder, open the Preferences folder.

In the Preferences folder, locate the file named Multi-User Prefs and throw it away. Empty the Trash.

Then restart the machine normally. It should now boot to the OS 9 on the hard drive, with no mention of users or passwords.

You may be able to borrow such a CD from someone in your area. Check with a local Apple User Group - most largee cities and universities have one.

Apple - User Groups

With the CD in the drive, restart or boot, then press the C key and keep it held down until you know the machine has started to boot to the CD.

Alternatively (and this may not work with a G3 - depends on firmware), restart or boot, immediately press the Option key (Alt on a PC keyboard)m keep it held down. This should bring up Startup Manager, a bright blue screen with a few large icons on it. If yhos works, use the mouse to select the icon representing the CD, then click the right-hand (straight) arrow icon.

Note - one of the problems with many non-Apple keyboards is compliance with the Mac-standard startup keyboard command set. Not all non-Apple keyboards comply with that set; some do.

Since you mentioned that more than one user was password protected, in OS 9 hat means it must be a Multiple Users setup rather than a hardware password.

A Multiple User account setup can not be defeated by resetting PRAM or doing any other thing to the hardware. Reason - Multiple User accounts (and associated passwords, etc.) are purely software-based. Multiple Users is loaded during the loading of the OS; unfortunately, it is designed to not be defeated by booting with 'extensions off'.

Not all CDs are bootable, of course. For one to be bootable, it must have a viable OS on it, one that is valid for the machine.

If your machine is a slot-loadig model, one of the original ones of that series initially released in October 1999, then it can use -

• an original Software Install CD which used OS 8.6.

* any retail (white label) OS 9.x Install CD.

• if its firmware has been updated, it may be able to boot to a retail disk for OS X 10.3 and, only for the 400MHz model, OS X 10.4.

Some users have reported that after the firmware on such early machines was updated, they would no longer boot to their original OEM disk, often not being able to boot to anything earlier than OS 9.1.

Can I use a Linux disc?

That's something I know nothing about; I've never tried using anything other than a Mac OS.

Perhaps someone else who has that info will post in with it.

Hey Don I've got a problem, I was given an iMac G3 just last year, just the computer and no keyboard or mouse.

Anyway there is already a registered person on the computer and I can't find any where to reset the computer.

Can you help??

What OS is the machine running?

I think it's running OSX 7...I think, I'll confirm that later.

No just found out its running OSX10.1

are you logged into that one account?

Yes you can use Linux, but it's "ssɐ ǝɥʇ uᴉ uᴉɐd ǝƃnɥ ɐ".

I've tried but it's basically impossible on a G3.

People have done it, but I certainly can't.