Install OSX prohibited symbol...



I have problems to install OSX on my Imac G3 Slot Loading.

When I try to install osx 10.2 Jaguar a "prohibited symbol" appear.
When I try to install osx 10.3 Panther a "prohibited symbol" appear.
The only successful install is when I install the 10.4 Tiger. WHY???

Why only Tiger, what happend with 10.2 and 10.3?


Doctor X


Need to know your full specifications. You generally cannot load a lesser OS than what you have on the machine currently.

Then we need to know what form of OS X you have? The disks that came with the computer? Retail disks? Non-retail disks?



The specs are: Imac G3 Slot Loading (year 2000). Came with OS 9.

Im trying to install os 10.2 and os 10.3 Retail disks and the "prohibited symbol" appear
in both cases, but there is no probblem with Tiger (retail too).


Chmod 760
Staff member
If you have 10.4.11 why would you want to go to 10.2 or 10.3 on that machine?
If you have either of those discs in, one of the options you can't select is the default, upgrade install. So, as long as those are the full retail discs, clean install, or erase install, should be possible. (But would lost all the data there)


The 'prohibited' symbol might mean that you have corrupted copies of those OS X installs.
Or, the older OS X installs are always on CDs. The Tiger (10.4) install is normally on a DVD, but was available on a set of (4?) CDs.
I'm guessing that the DVD is the difference. Your DVD/CD-ROM drive may not boot to CDs, but will with DVDs. Unusual, but possible...
If your install sets are ALL on CDs, then that shoots my theory right in the head!... Still could just be bad disks for 10.2 or 10.3


U.S.D.A. Prime
Where did the 10.2 and 10.3 install CDs/DVDs come from? Retail versions? Gray colored disks from a different model of Mac? Burned copies from somewhere?


Because my imac has 256mb of ram.
I can´t select any option because the retail disks (os 10.2 and 10.3) didnt boot, they boot
30 seconds and the prohibited symbol appear, before the install options.


Any of those OS X versions will install with 256MB of RAM.
What color are the labels on those 10.2 and 10.3 installers?

Is there a reason that you need to get those 10.2 and 10.3 installers to work, now that you have 10.4 installed?


If I understand correctly, you already have Tiger installed. You cannot install a lesser (older) OS than is what is currently on the machine. If you are committed to 10.2 or 10.3, you will need to start-up from the desired install disc but instead of installing, choose disc utility then erase the original volume. Once erased, install to your hearts content.

Of course I wonder why you want to go backwards, but it's your life.


The OP should not be getting the 'prohibited' symbol when trying to boot to a compatible installer disk. That would not be affected in any way by the version of OS X that is installed on the hard drive. And, the OP stated that the installer never gets to the installer/options screen.


I did everything, I copied the CDs to DVDs and nothing.
All the OS that I have works on my G3 blue and White.

Jaguar feels faster, boot faster and reacts faster on my G3 Blue and White than Tiger.


Ah, well this is easy.
Connect your iMac to that Blue&White G3, using a firewire cable.
Put your 10.2 (or 10.3) installer in the B&W drive.
Start your iMac in Target mode (holding the T key during boot until you see the floating firewire icon)
Boot the B&W to that installer, and choose the iMac hard drive as the install destination. You'll need to choose the Option to Erase and Install, especially if you go back to 10.2 from 10.4


Good idea, I don´t have any firewire cable at this moment.
I think the only solution is a force installation or keep the os 10.4.11