Mac OS X 10.6: Reverting to a previous Mac OS X version
If you’ve used Time Machine to back up your computer, you can easily revert to a previous version of Mac OS X if you’re experiencing trouble after installing an update.
Important:Reverting to the previous version of Mac OS X will erase any changes you’ve made to the files on your computer since you installed the new version of Mac OS X. To save new or revised files, copy them onto a different disk or back them up using Time Machine before you follow these instructions. Use Time Machine only if you’re reverting to a previous version of Mac OS X 10.5 (Leopard) or 10.6 (Snow Leopard), because Time Machine is not available with Mac OS X 10.4 or earlier.
To revert to a previous version of Mac OS X:
Insert the Mac OS X installation disc in your computer’s optical drive (or an optical drive connected to your computer), and then choose Apple menu > Restart.
Note:If you’re using another computer’s optical drive, make sure your computer is set up for remote installation, and then go to step 3. For more information about remote installation, see:
In the Installer, click Utilities, and then click Restart.
When the Language Chooser appears, select your language, and then click the Continue button (looks like an arrow).
In the Installer, choose Utilities > Restore System From Backup.
In the Restore Your System dialog, click Continue.
Select your Time Machine backup disk.
Select the Time Machine backup you want to restore. To restore your computer to the state it was in before you installed the new version of Mac OS X, choose the most recent backup.
Follow the onscreen instructions.
If you backed up any individual files as described in the Important message above, you can restore them now. If you backed them up using Time Machine, recover them using the Time Machine application. (You’ll find the Time Machine application in the Dock or in the Applications folder.)