5 Replies Latest reply: Sep 25, 2011 12:23 PM by Kappy
Michael Schulz Level 1 (55 points)

I want to sell my MacBook and want to re-install Snow Leopard.

Currently Lion is installed but I want to erase all my data, settings etc.

and install Snow Leopard ( I have the DVD ! ).


How can I do this ? Mounting the DVD with SL under Lion trigges an error

message telling me that this can't be done.

iMac Intel, Mac OS X (10.7)
  • Kappy Level 10 (263,335 points)

    Prepare Your Mac for Sale


    Boot from the Snow Leopard Installer Disc One that came with the computer.  After the installer loads select your language and click on the Continue button.  When the menu bar appears select Disk Utility from the Utilities menu.  After DU loads select the startup volume from the left side list then click on the Erase tab.  Set the format type to Mac OS Extended (Journaled) then click on the Options button.  Select the one pass Zero Data option and click on the OK button.  Then click on the Erase button.


    Note: You can skip the Zero Data option if you are not concerned about removing sensitive personal data from the hard drive.  If you choose to skip this part of the process then it is possible for others to recover data from the hard drive.  The Zero Data procedure will prevent others from getting access to your personal information.


    This process will take 30 minutes to several hours depending upon the size of the hard drive.  After formatting has completed quit DU and return to the installer.  Now complete the OS X installation.  At the completion of the installation do not restart the computer.  Instead just shut it off.  The next user will be presented with the Setup Assistant when they turn on the computer just as it would if new out of the box.


    Booting From An OS X Installer Disc


    1. Insert OS X Installer Disc into the optical drive.

    2. Restart the computer.

    3. Immediately after the chime press and hold down the "C" key.

    4. Release the key when the spinning gear below the dark gray Apple logo appears.

    5. Wait for installer to finish loading.

  • Kappy Level 10 (263,335 points)

    Interesting tutorial, Eric. One thing I noted about the restoring from backups. If the backup is done while Lion was installed, then it cannot be used to downgrade to Snow Leopard. Seems that they omitted this in the tutorial.

  • Eric Ross Level 6 (11,665 points)

    You are correct, I over looked that myself.  Thanks for the heads up Kappy.

  • Kappy Level 10 (263,335 points)

    We need to thank Pondini. I learned that from his Time Machine information. He pointed that out to me to include when providing a downgrade procedure.


    Thank You, Pondini.