macOS Install & setup

Clean install macOS from USB

Full macOS reinstall from USB when Recovery is unavailable or you want a known-good installer.

18 min read Intermediate Updated 9 Jun 2026
macOS library Start the guide

Step-by-step guide

Work through each section in order. Stop when your issue is resolved — you do not need every step for every situation.

Warning

Create a Time Machine backup before major updates, disk operations, or security changes on macOS.

What you will achieve

Full macOS reinstall from USB when Recovery is unavailable or you want a known-good installer.

1) Build installer USB

softwareupdate --list-full-installers
sudo /Applications/Install\ macOS\ Sonoma.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB

2) Boot from USB installer

  • Apple Silicon: hold power button to Loading startup options.
  • Intel: restart and hold Option.

3) Erase and install

  1. Open Disk Utility, show all devices, erase system volume group correctly (usually APFS, GUID).
  2. Run Install macOS and complete setup.

Related guides

clean install macos usb installer

Related guides

Continue with these next if you are building a fuller setup or troubleshooting path.

Install & setup
Reinstall macOS from Recovery
Use macOS Recovery to reinstall the OS — choose the right path (keep data vs erase), with Apple Silicon and Intel entry methods spelled out.
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Install & setup
Create a macOS recovery USB installer
Keep a USB installer handy before the Mac will not boot — official Apple method.
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