Wipe and Reinstall macOS

General Information

Note: This process will remove all files, content, and settings from the computer. A backup of any crucial information should be performed before proceeding with this article.

Important Terms

  • macOS – Macintosh’s Operating System. To find out what version of macOS your computer is running, go to Apple > About This Mac.

Hardware Requirements

In order to Internet Restore a Mac, it must meet the following criteria:

  • Desktops
    • iMac (21.5-inch, Mid 2011 or newer)
    • iMac (27-inch, Mid 2011 or newer)
    • Mac Mini (Mid 2010 or newer)
  • Laptops
    • MacBook (13-inch, Mid 2010 or newer)
    • MacBook Air (11-inch, Late 2010 or newer)
    • MacBook Air (13-inch, Late 2010 or newer)
    • MacBook Pro (13-inch, Early 2011 or newer)
    • MacBook Pro (15-inch, Early 2011 or newer)
    • MacBook Pro (17-inch, Early 2011 or newer)

Any models that are not in the list above are not compatible and should be sent to Property Surplus.

Step 1: Boot into Apple Internet Recovery

  1. Make sure the Mac is completely shut down.
  2. If an Ethernet port is available, plug in an Ethernet cable into a hot port.
  3. Press the power button.
  4. Immediately hold down the following keyboard combination: Command+Option+R.
  5. If the Mac is not hard-wired, you will need to connect to the PCPS-Apple Wi-Fi with the password applesetup.
  6. Hold the keys down until a spinning globe icon appears.

If the globe icon does not appear, the most likely cause is that the key combination was either not pressed quickly enough, or was released too soon. You can shut the machine down by holding the power button for at least 10-seconds and retrying the steps above.

  1. Make sure the Mac is completely shut down.
  2. If an Ethernet port is available, plug in an Ethernet cable into a hot port.
  3. Press and hold the power button until “Loading startup options” appears.
  4. Click Options.
  5. Click Continue.
  6. If the Mac is not hard-wired, you will need to connect to the PCPS-Apple Wi-Fi with the password applesetup.

Step 2: Erase Hard Drive

  1. Click Disk Utility.
  2. Click Continue.
  3. On the toolbar of Disk Utility, click the View drop-down.
  4. Click Show All Devices.
  5. In the left column, locate the Internal section.
  6. Select the top-most, non-indented option. This will usually have a name similar to “APPLE SSD SM025…”.
    1. Note: If you do not see an Internal section or do not see any drives under the Internal section, the hard drive my have hardware problems. An EERS work order should be submitted for the bad hard drive.
  7. On the toolbar, click Erase.
  8. In the Name field, input Macintosh HD.
  9. In the Format field, select APFS.
    1. Note: If APFS is not an option, select Mac OS Extended (Journaled) instead.
  10. In the Scheme field, select GUID Partition Map.
  11. Click Erase.
  12. Click Done.
  13. Quit Disk utility by navigating to Disk Utility > Quit Disk Utility.
  1. Click Disk Utility.
  2. Click Continue.
  3. On the toolbar of Disk Utility, click the View drop-down.
  4. Click Show All Devices.
  5. In the left column, locate the Internal section.
  6. Select the top-most, non-indented option. This will usually have a name similar to “APPLE SSD SM025…”.
    1. Note: If you do not see an Internal section or do not see any drives under the Internal section, the hard drive my have hardware problems. An EERS work order should be submitted for the bad hard drive.
  7. On the toolbar, click Erase.
  8. In the Name field, input Macintosh HD.
  9. In the Format field, select APFS.
    1. Note: If APFS is not an option, select Mac OS Extended (Journaled) instead.
  10. In the Scheme field, select GUID Partition Map.
  11. Click Erase.
  12. Click Erase Mac…
  13. Click Erase Mac and Restart. The Mac will automatically reboot and erase all data, including the Operating System, software, and user information from the drive.

Step 3: Reinstall Operating System

  1. Click Reinstall macOS.
  2. Click Continue.
  3. Click Continue.
  4. Click Agree.
  5. Click Agree.
  6. Click the Macintosh HD icon.
  7. Click Continue. The Operating System will begin to install and the computer may reboot several times.

Depending on internet and computer speed, installation will take roughly 45 minutes.

  1. At the Language screen, select English.
  2. Click Continue.
  3. Wait for the Activate Mac screen to finish.
  4. Click Exit to Recovery.
  5. Click Reinstall macOS.
  6. Click Continue.
  7. Click Continue.
  8. Click Agree.
  9. Click Agree.
  10. Click the Macintosh HD icon.
  11. Click Continue. The Operating System will begin to install and the computer may reboot several times.

Depending on internet and computer speed, installation will take roughly 45 minutes.

Step 4: Apple Setup Assistant

If the Mac is connected via a hard-wired Ethernet, do not click on anything. The Setup Assistant will automatically progress through the enrollment.

If you are connected via Wi-Fi, you will need to:

  1. Select United States.
  2. Click Continue.
  3. Select U.S.
  4. Click Continue. The Remote Management or Configuration Available screen may appear to be frozen while it processes.
  5. At the Time Zone screen, check Set time zone automatically using current location.
  6. Click Turn on Location Services. If you receive an error that the computer cannot determine your location, it can be ignore.
  7. Click Continue.

Step 5: First Log In

  1. Click Other.
  2. In the username field, type: completesetup
  3. In the password field, type: setup
  4. Hit Enter.

After a few moments, the Mac Registration app will launch.

Step 6: Mac Registration

  1. On the Mac Registration app, click Register.
  2. Fill out all of the fields:
    1. Assign to User – This should be FirstName.LastName of the person who will oversee the Mac.
    2. Computer SAP Number – This should be computer’s 8-digit SAP number (not the user’s SAP number).
    3. Location – Select the school or department that the user belongs to.
    4. Computer Role – If the Mac is to be used by staff members, select Staff. If the Mac is to be used by students, select Students.
  3. Click Register.

The app will install required software and settings. Once it is complete, it will reboot the computer. After the reboot, the user can now log in with their network credentials.