macOS Recovery Disk decisions

Reinstall macOS from Recovery

Use Recovery when macOS is unstable, you are handing off a Mac, or you want a clean OS layer. Choose between “keep my data” reinstall vs “erase everything” with care.

macOS library Start the checklist

What this guide covers

Enter Recovery, decide whether to erase, reinstall the OS, and sanity-check the result. Apple documents change over time — treat firmware menus as authoritative on your exact model.

Warning

Erasing your internal disk removes personal data on that volume. If you choose Erase, assume recovery will require your backups.

0) Backup first (non-negotiable)

  • Time Machine to an external drive is the simplest full-Mac backup for many users.
  • Copy critical files to a second location (cloud or external disk) even if you also use Time Machine.
  • For managed Macs, follow your IT policy — reinstalling may break enrollment expectations.

1) Two common goals (pick one)

A) Reinstall macOS without erasing (lighter touch)

Repairs/replaces OS components while typically leaving user data in place. This is not a guaranteed privacy wipe.

B) Erase internal disk + reinstall (stronger reset)

Best when selling a Mac, removing your personal data, or dealing with deep corruption. This is the “start fresh” path.

2) Enter macOS Recovery

Apple Silicon and Intel use different startup keys. If your Mac uses a firmware password, you will need that first.

  • Apple Silicon: shut down, press and hold the power button until “Loading startup options” appears, choose Options.
  • Intel: restart and hold Command + R (or Shift + Command + R where appropriate for older installs).

3) If erasing: Disk Utility

  1. Open Disk Utility from the Recovery environment.
  2. Select the correct internal container/disk (double-check disk name and size).
  3. Erase using Apple’s current recommended scheme/format for your macOS version (APFS is typical for modern releases).

4) Reinstall macOS

  1. Return to the Recovery main window and choose Reinstall macOS.
  2. Select the destination volume and allow the download/install process to finish — it can take time and multiple reboots.
  3. If Wi‑Fi is required, connect when prompted (Ethernet is usually the most reliable during install).
If activation or download fails

Check date/time, network, and try a different network. For stubborn downloads, Ethernet and a known-good router often beat captive Wi‑Fi.

5) First login checks

  • Confirm you can log in and reach the internet.
  • Run Software Update until no required updates remain.
  • Open Disk Utility and verify the volume looks healthy after install.
  • Restore a test file from backup to validate restore access.