Wipe and reinstall macOS

How To: Erase and Reinstall macOS Using Recovery Mode

This article provides instructions for erasing and reinstalling macOS using Recovery Mode when the “Erase All Contents and Settings” option is unavailable.

Audience

This article is intended for faculty, staff, and student employees who are preparing Apple computers for reinstallation or reassignment.

Platform

Apple macOS (Intel and Apple Silicon)

Contents

Check for Erase All Contents and Settings

  1. Check if the Erase All Contents and Settings option is available.
  2. If this option is available, use it to reset the device. You do not need to continue with this guide.

Boot into Recovery Mode

  1. Follow the appropriate instructions to boot into Recovery Mode:

If Prompted for a Password or Recovery Key

  1. Click Recovery Assistant in the menu bar.
  2. Select Erase Mac….
  3. Follow the on-screen instructions to erase the device.

Erase the Macintosh HD Drive

  1. Select Disk Utility from the Recovery menu.
    Disk Utility selected in Recovery Mode
  2. Select Macintosh HD from the left-hand sidebar.
  3. Click Erase at the top of the window.
    Erase button selected for Macintosh HD in Disk Utility
  4. Ensure the following settings:
    • Name: Macintosh HD
    • Format: APFS
    Click Erase to confirm.
    Erase confirmation window showing Macintosh HD with APFS format
  5. If prompted to restart, click Restart.
  6. Repeat the erase steps in Disk Utility if multiple volumes remain. You should have only one volume named Macintosh HD.
    Final single volume view named Macintosh HD

Reinstall macOS

  1. After erasing the drive, the system will return to the Recovery menu.
  2. Select Reinstall macOS.
    Reinstall macOS option highlighted in the Recovery menu
  3. Click Continue.
  4. Click Accept, then click Agree.
  5. Select your Macintosh HD volume and click Install.
  6. Wait for the installation to complete. The Mac may restart during the process.
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