Downgrading from Leopard

Maybe you and your Mac just weren’t ready.

Here’s the scenario: In the months leading up to Leopard, you and many others among the Mac faithful started getting excited about the new features. Your computer has a few years on it and you wonder if it’ll run the new operating system. Then Leopard is released and you read the official minimum system requirements. Yes! According to Apple, it will run on your G4 computer! You run out and buy it, then install it and start taking advantage of all the great new features.

This is what happened to me. Although I treated myself to a brand spanking new iMac a few months ago, I still use my little 12″ G4 PowerBook extensively for mobile computing. The idea of being able to use Back to My Mac to access my iMac while I was on the road was too enticing to pass up.

According to the minimum system requirements, its 867 MHz PowerPC G4 processor and 640 MB of RAM would be enough to run Leopard. It did. But not very well.

The problem I encountered was the old spinning beach ball. Like the computer was falling asleep without closing its eyes. Sometimes I’d have to wait five or more minutes for it to get back to work. This soon drove me nuts and I decided to downgrade the machine back to Tiger.

I need to note here that I like Leopard very much. I have it installed on my production machine (the iMac), as well as the 15″ MacBook Pro I use as my “test mule.” I’m not recommending that you downgrade from Leopard to Tiger if you’re not having problems. But if you, like me, installed Tiger on an older, slower Mac — especially a G4 (what were we thinking?) — downgrading is an option you might want to consider. (A better but more costly option might be to get a new Mac.)

That said, here’s how you can get the job done. Please read this entire article before starting; there’s important information about the items you may lose after these steps are completed.

1. Back up your Home folder to another disk. If you have a .Mac account, sync your Address Book, iCal events, and Mail settings to .Mac. (You can use this as a backup to easily restore your data after the downgrade.)
2. Insert the Mac OS X 10.4 Tiger installation disc in your computer’s CD/DVD drive.
3. When the Mac OS X Install DVD window opens, double-click Install Mac OS X.
4. When prompted, click Restart and enter your password. Your computer should restart from the DVD.
5. Follow the prompts that appear onscreen to select your language and advance through the screens until you get to the Select a Destination screen.
6. Select your hard disk as the destination. It will probably appear with a red X, indicating that Tiger cannot be installed on that volume.
7. Click the Options button.
8. In the Options dialog that appears, select Archive and Install. (It may already be selected.) You will not be able to turn on the Preserve Users and Network Settings check box. Click OK.
9. Click Continue and follow the remaining prompts to install Tiger on your computer.
10. At the end of the installation, the computer restarts and displays the Mac OS X Setup Assistant screens. Follow the prompts to set up your computer. You will not be able to copy existing setup information from the Previous Systems folder that now resides on your hard disk or from a backup because those settings were created with a more advanced version of Mac OS than what is now installed.

In the Options dialog, you could also choose Erase and Install, but that would erase everything on you hard disk. Although this is always the best option for installing system software since it does a real “clean” installation, you must prepare by backing up all of your documents before doing the installation. Do not choose Erase and Install unless you’ve backed up your hard disk to another disk you can restore from.

When the entire process is done, you’ll have a Previous Systems folder on your hard disk’s root level. You might also have some other folders that were created by Leopard and have been left behind in the downgrade. For example, I found one called net and another named home that appeared to be empty. If these folders are empty, you can delete them.

Around this time, if you have an Internet connection, you’ll be prompted to update Mac OS X 10.4 and other components. Perform the update. It’ll bring Tiger up to the most current version, which includes security and bug fixes, as well as system enhancements.

When that’s done, you can also go through the contents of the Previous Systems folder and delete the applications and settings files you don’t need. For example, the Applications folder inside the Previous System 1 folder will include all the Leopard applications your Tiger computer can’t run: Address Book, Mail, QuickTime Player, etc. T Tiger-compatible version of most of these applications can be found in the Applications folder on your hard disk’s root level. For some reason, however, iCal 3 is left behind and it won’t run on Tiger. (I’ve reported that as a bug to Apple.) You’ll have to get a copy of iCal 2 from another source and install that on your downgraded disk if you want to use iCal.

The data from your Address Book and iCal files and any mail stored in the Mail application are in a format that Tiger can’t read. If you have a .Mac account and synced before the downgrade, just sync again to replace the existing data on your computer (which should be nothing) with what’s on .Mac. That’ll restore much of the information. You may also be able to import your Mail messages from the Library folder in your Previous Systems folder (dig to find it) to the Tiger version of Mail.

And, of course, you’ll have to find all your old preferences files from the Previous Systems folder and put them in the right place so they’re recognized and used by your computer.

As you can see, this isn’t a small task. In my case, I put it off as long as I could. But when you spend more time waiting than working, you know you’ve got to take steps to fix the problem — even if they’re drastic steps.