How to uninstall OS X Mountain Lion 10.8 and go back to Snow Leopard 10.6.8?
After getting fedup/angry with the most useless OS ever, i needed to kick out this junk and replace it with the good old 10.6.8 Snow Leopard:
Important: If you have a MacBook Air, you'll need an Apple USB SuperDrive or USB Software Reinstall Drive to complete this procedure in Snow Leopard.
This procedure has four parts:
Part one: Erase the hard drive
To ensure that the hard drive's partition does not have an issue, perform the following procedure to erase the drive and reset the partition type.Important: This procedure will completely erase your hard drive. If you have installed Microsoft Windows using Boot Camp, or have multiple partitions, this procedure will erase all of the partitions on the selected drive.
- Turn on the computer.
- Insert the Mac OS X v10.6 Install DVD into the optical drive, or the MacBook Air's USB Software Reinstall Drive into the USB port.
- Restart the computer, and immediately press and hold the "C" key while the computer starts up. The computer will start up using the installation media. Alternatively, you can press and hold the Option key at startup to select the volume containing the installer.
- If you are using a wireless mouse or trackpad, you may be prompted to turn it on so that the computer can discover it.
- Select a language, then press the right arrow key.
- From the Utilities menu, choose Disk Utility.
- Select the drive to erase. Usually, the drive capacity, vendor, and model number are listed as the name of the volume(s).
- Click the Partition tab.
- From the "Volume Scheme" pop-up menu, choose 1 partition.
- Click Options.
- Set the partition scheme to Master Boot Record, then click OK.
- From the Format pop-up menu on the right side, choose any choice other than "Mac OS Extended (Journaled)". For example, you can choose "Mac OS Extended".
- Click Apply. The drive will be erased.
- Click Options again.
- Set the partition scheme to GUID, then click OK.
- From the Format pop-up menu on the right side, choose "Mac OS Extended (Journaled)".
- Click Apply. The drive will be erased again.
- After the process is complete, choose Quit Disk Utility from the Disk Utility menu.
Part two: Reinstall the operating system
Important: If you want to restore Mac OS X and your files from a Time Machine backup, stop here and use the steps in the "Restoring your entire system from a backup" section of this article.
- When the Mac OS X v10.6 Snow Leopard Installer screen appears, click Continue.
- When the license agreement appears, click Agree.
- Select the disk you erased in part one. It should now be highlighted with a green arrow.
- Click Install. A status bar appears on the bottom of the screen while Mac OS X installs.
- An Additional Information screen appears, advising you that you operating system has been installed. Click Continue.
- An Install Succeeded screen appears. Click Restart.
Part three: Complete the Mac OS X Setup Assistant
- When the restart has completed, a welcome video plays, then country/region selection screen appears.
- Select your country or region and click Continue.
- Select a keyboard layout and click Continue.
- A migration screen appears. If you wish to migrate your data from another Macintosh. If you do not wish to migrate, or want to migrate later, select "Do not transfer my information now" and click Continue.
- A Wireless Service screen appears if you have wireless services available within range of your computer. Select "On" and click Continue.
- If the network is password protected, you be asked for a password when you select it. Type the password and click Continue.
- An Apple ID screen appears. This is used to purchase content from the iTunes store. You can use MobileMe or .Mac usernames here as well. When complete, click Continue.
- If you do not have an Apple ID or MobileMe account, click Continue to move to the next screen.
- A Registration Information screen appears. You are not required to fill this out, but it is helpful if you do. When complete, click Continue and your product registration will be sent immediately.
- If Mac OS X servers are available on your network, you'll be asked if you'd like to log on to them. If not, click Continue.
- A Create Your Account screen appears. This will be used to create a User Account with Login ID and Password for you computer. You should remember this password. You'll be asked for it when you install new software or perform other administrative tasks on your computer. When complete, click Continue and your account will be created immediately.
- A screen to select your user picture appears. Take a snapshot with the built-in camera or select a picture from your Library. When complete, click Continue.
- A MobileMe screen appears. Select an option and click Continue.
- A Thank You screen appears. Click Go to complete the Mac OS X Setup Assistant.
- Eject the installation media by dragging its icon to the Trash.
Part four: Install bundled applications
- To install the bundled applications, locate the Applications Install Disc or Software Reinstall Drive that came with your computer.
Note: You may see a Software Update icon bouncing in your Dock. You can quit or ignore this for now. - Insert the Applications Install Disc into the optical drive, or insert the MacBook Air Software Reinstall Drive into the USB port.
- The disc will mount and an Applications Install Disk dialog appears. Double-click on Install Bundled Software to install your iLife applications. If you are using the MacBook Air Software Reinstall Drive, double-click the Install iLife icon.
- A dialog appears asking if you want to run the package. Click Continue.
- The Bundled Software Applications Installer screen appears. Click Continue.
- A software license screen appears. Click Continue, then click Agree to accept the terms.
- A select destination dialog appears. Make sure the partition with the green arrow is the correct destination, then click Continue.
- To install all the bundled applications, click Install.
- To select individual applications, click Customize. Click the disclosure triangle next to Bundled Applications to select individual applications, then click Install. Clicking Standard Install on the Customize screen installs all the applications.
- Type the password you created in Part Three, step 11 to start the installation.
- A restart dialog appears. Click Continue Installation.
- An Install was Successful screen appears. Click Restart to complete the restore process.
As an succsessfull iOS/OS X App developer for 5/6 years, i predict that this is the end of Apple. Pointless products, incompetens in every department, overpriced, greedy, just plain dangerous...
OS X Mountain Lion (10.8), Disabling Gatekeeper, User Tips