HT204904: How to reinstall OS X

Learn about How to reinstall OS X
shingywingy

Q: I'm selling my computer but when I get to step 3 (reinstalling OS X) an error message keeps coming up telling me I cannot install an older version of os x on the computer because there is a newer version installed. Help?

I'm selling my computer but when I get to step 3 (reinstalling OS X) an error message keeps coming up telling me I cannot install an older version of os x on the computer because there is a newer version installed. Help?

MacBook Air

Posted on Aug 15, 2016 5:38 AM

Close

Q: I'm selling my computer but when I get to step 3 (reinstalling OS X) an error message keeps coming up telling me I cannot install ... more

  • All replies
  • Helpful answers

  • by JimmyCMPIT,Apple recommended

    JimmyCMPIT JimmyCMPIT Aug 15, 2016 5:39 AM in response to shingywingy
    Level 5 (6,933 points)
    Mac OS X
    Aug 15, 2016 5:39 AM in response to shingywingy

    What to do before selling or giving away your Mac - Apple Support

     

    you can't downgrade to anything less than what your computer shipped with and if something newer is on there now you need to partition it off the drive entirely.

  • by shingywingy,

    shingywingy shingywingy Aug 15, 2016 5:42 AM in response to JimmyCMPIT
    Level 1 (4 points)
    Mac OS X
    Aug 15, 2016 5:42 AM in response to JimmyCMPIT

    So it won't give me the option of reinstalling the version that's currently on there -- how do I partition it off the drive?

     

    Thank you!

  • by JimmyCMPIT,

    JimmyCMPIT JimmyCMPIT Aug 15, 2016 5:51 AM in response to shingywingy
    Level 5 (6,933 points)
    Mac OS X
    Aug 15, 2016 5:51 AM in response to shingywingy

    if you want the data you need to back it up

    then depending on the age of the computer you can use recovery mode to reinstall a clean copy of the OS it came with

    About OS X Recovery - Apple Support

    or if your computer predates this feature you will need the disks that came with the computer or an install DVD that is compatible with your computer, boot to that DVD and wipe the drive then reinstall from the DVD.

    before you do any of this what computer do you have, what year, what OS are you trying to install?

     

    you can just screen shot this from

    >About this mac

    don't include the serial #, no one but Apple ever needs it.

     

    Screen Shot 2016-08-15 at 8.50.17 AM.png

  • by shingywingy,

    shingywingy shingywingy Aug 15, 2016 6:05 AM in response to JimmyCMPIT
    Level 1 (4 points)
    Mac OS X
    Aug 15, 2016 6:05 AM in response to JimmyCMPIT

    So, that's what I tried to do.

     

    It's a MacBook Air "13, Early 2015 model. I've already backed up the files I need and I went through all of the steps to remove my personal information from the computer. I went in to start from OS X Recovery, and went through all the steps for os x internet recovery until the "OS X Utilities" window came up.

     

    That's where I got stuck. When I hit "Reinstall OS X" (Reinstall a new copy of OS X) that's when I get the error -- it won't reinstall the last version of of the OS X but wants to install the version that originally came with my Mac -- which Apple doesn't allow.

  • by JimmyCMPIT,

    JimmyCMPIT JimmyCMPIT Aug 15, 2016 6:52 AM in response to shingywingy
    Level 5 (6,933 points)
    Mac OS X
    Aug 15, 2016 6:52 AM in response to shingywingy

    use the internet recovery option to install the OS that shipped with the computer

    you will need to erase the drive before this can happen using the Disk Utility.

    this is done from the recovery boot, you will not be able to erase the disk if you boot to the OS normally.

     

    Shut down and disconnect all external devices before proceeding.

  • by shingywingy,

    shingywingy shingywingy Aug 15, 2016 4:24 PM in response to JimmyCMPIT
    Level 1 (4 points)
    Mac OS X
    Aug 15, 2016 4:24 PM in response to JimmyCMPIT

    DO I go into disk utility and erase the data on the disk? will that let me reinstall the OS? Sorry -- I'm a little nervous to hit erase in case I can't recover.

  • by John Galt,

    John Galt John Galt Aug 15, 2016 9:18 PM in response to shingywingy
    Level 8 (48,544 points)
    Mac OS X
    Aug 15, 2016 9:18 PM in response to shingywingy

    You won't be able to reinstall a Mac's originally installed OS until you erase it first. That's a prerequisite for selling any Mac.

     

    shingywingy wrote:

     

     

    DO I go into disk utility and erase the data on the disk? will that let me reinstall the OS?

     

    Yes. The operating system will be reinstalled from a separate partition dedicated to that purpose.

     

    Even if you were to make a mistake and remove or erase that partition, or if the solid state memory containing the entire Mac's storage were to be removed and replaced with a completely empty one, your model MacBook Air contains firmware providing the ability to re-create the Recovery Partition required to reinstall OS X. It's brilliant... as long as you have a reasonably fast Internet connection, because the entire download is on the order of 8 GB or so.

     

    You already received competent assistance from JimmyCMPIT, so just follow his instructions.