How to Clean Install macOS 12 Monterey: 4 Steps

Rosa Reyes
time August 25, 2021 Preview 808
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The beta version of macOS Monterey has been released for some time. It always makes us excited to install and try the new features & enhanced performances of an updated macOS, especially this macOS brings us: FaceTime’s SharePlay to share your screen, Safari’s streamlined tab bars, new Focus app helps you concentrate, universal control to work across Apple devices easily, etc.

Instead of upgrading, you may have decided to clean install macOS, for the reason that you want to erase your Mac for a new start, or for the reason that you are going to transfer the Mac’s ownership. In this post, we will show you how to clean install macOS Monterey from a bootable USB drive, also give the solution if files lost after macOS Monterey install.

Requirements to Clean Install macOS Monterey

Not all Apple laptop and desktop can have a clean install of macOS 12, Monterey can run on following models:

  • iMac---Late 2015 and later
  • iMac Pro---2017 and later
  • Mac mini---Late 2014 and later
  • Mac Pro---Late 2013 and later
  • MacBook Air---Early 2015 and later
  • MacBook---Early 2016 and later
  • MacBook Pro---Early 2015 and later

The installer of macOS Monterey is about 12GB, but you still need extra space to get it work properly and leave enough space to install some important apps on your Mac to check if your workflow can be elevated efficiently. So, make sure at least 16 GB available on your hard drive to clean install this new version.

Also, prepare 2 external drives, one to back up files, the other one to create the bootable installer (at least 16GB). When clean install macOS, we are often recommended to install from a bootable USB, which is able to install the OS from scratch, especially in the case that our current OS runs slowly/improperly, or you want to install macOS Monterey on different devices. 

How to Clean Install macOS Monterey on Mac from Bootable USB?

There are 3 steps to clean install macOS, the first, also the most important step is always to back up your files to external hard drive or cloud-based accounts. Now, let’s check out the steps.

Step 1. Back Up File to External Drive or iCloud

Option 1. Back up all files to external drive via TimeMachine

  1. Connect the external drive to your Mac.
  2. Click on Apple menu>System Preferences>Time Machine.
  3. Click on Backup Disk.backup file

Option 2. Backup important files online

  1. Click on Apple menu>System Preferences>iCloud.
  2. Login in with Apple ID.
  3. Tweak the settings.

Step 2. Create A Bootable Installer for macOS Monterey on USB

  1. First, download the macOS Monterey beta version to your Mac here.
  2. Run Terminal app in Finder>Application.
  3. Copy and paste the command line “sudo /Applications/Install\ macOS\ 12\ --volume /Volumes/MyVolume” in Terminal. You need to replace MyVolume with the name of your USB drive, check Step 4.terminal command
  4. Now, connect your USB to Mac, open Disk Utility, click on External>USB Drive>Find the name in Mount Point, and input to replace MyVolume in Terminal. usb drive name
  5. Back in the Terminal interface, press Return and enter your password to run the command.

Step 3. Adjust Startup Security Options to Enable Booting from USB

  1. Press and hold Command+R, you will see the apple logo and then the interface prompting you to enter logo
  2. After you have entered the Recovery Mode, click on Utilities>Startup Security Utility.startup security tool
  3. Then check before the box No Security and Allow booting from external or removable media, click the Close button to save the settings.startup security options
  4. Click on Apple logo>Shut down.

Step 4. Clean Install macOS Monterey

  1. Press and hold Option key until you are prompted to enter the password, input it to continue.
  2. Choose the bootable USB drive.choose usb drive boot
  3. Choose Disk Utility.goto disk utility
  4. Select your Mac internal hard drive and click Erase to clean the entire disk up for macOS Monterey installation.erase mac
  5. When the erasing is done, close the Disk Utility Windows and click on Install macOS 12 Beta to start the clean installation from your USB.install beta
  6. Follow the instructions and tweak the OS settings according to your needs.

What If Files Lost After Installing macOS Monterey?

Generally speaking, if you have backed up your files and do the installation properly, it is not likely to lose files. But if you get the bad luck and lost files ater macOS Monterey update, try Cisdem Data Recovery, the best mac recovery tool to get your files back.

Cisdem Data Recovery for Mac is designed to recover lost, deleted and formatted files on mac, under different situations like macOS update, downgrade, hard drive formatting, accidental file deletion, etc. It not only supports recovering files from Mac internal hard drive, but recovers files from Mac external storage devices (SD Card, USB, removable device, etc.)

Main Features of Cisdem Data Recovery

  • 5 recovery modes for different data loss situations
  • Recover lost, deleted, formatted files
  • Restore files from Mac internal and external drive
  • Support recovery on 200+ files: documents, videos, audios, photos, archives, etc.
  • Preview recoverable files
  • Fast and easy to use

How to Recover Lost File After Installing macOS Monterey?

  1. Download and install Cisdem Data Recovery on your Mac.
    Free Download
  2. Choose a recovery mode, Basic refers to Quick scan, while Advanced refers to deep scan. recover files after monterey install 1
  3. Choose the hard drive and click Scan to start scanning the disk. recover files after monterey install 2
  4. Then preview the recoverable files and select them, click Recover to get them all back to your Mac. preview files

When to Clean Install Official Version of macOS Monterey?

This fall, the date is not announced.

Like other new macOS release, the official version of macOS Monterey comes this fall too. From Jun 11 to now, Apple has updated Monterey beta version for many times, before getting all things fixed per the beta testing results, it is not possible for mac users to install the official version before fall, so, let’s just wait.


If you have decided to clean install macOS Monterey on your device, keep in mind to back up your files before any action. A clean install macOS make your Mac brand new and run faster, but any data loss would be a tragic, so, never overlook the backup step.

Rosa Reyes
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Rosa has worked in Mac software industry for more than eight years. She believes that the purpose of software is to make life better and work more productively. In addition to writing, Rosa is also an avid runner.

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