Apple has a new version of macOS called Monterey that you’ll find in the Software Update pane of System Preferences. However, if you want to update the old method, we’ll show you what you need to create a bootable macOS Monterey installation drive. (Editor’s note: These instructions are for the official version of macOS Monterey, not a beta version. Made on a Mac running macOS 11 Big Sur.)
Get an external drive and maybe an adapter
The macOS Monterey installer is over 12GB in size, so you need an external USB drive that can hold that much data. The drive can be a thumb drive, hard drive, or SSD.
If you have a 2015 or newer Mac laptop that has Thunderbolt/USB-C ports, you may need Apple’s $19 USB to USB-C Adapter. This will allow you to connect a storage device that uses a USB Type-A connector. If you don’t have an external drive and you have a USB-C Mac laptop, you can buy the SanDisk Ultra USB Type-C flash drive, which has a USB-C connector. You can get the model number SDCZ460-032G-G46 for $9 on Amazon.
You need to erase and format the drive to Mac OS Extended (Journaled). You can do this in the Disk Utility app for Mac, located in the Utilities folder within Applications.
Get the macOS Monterey Installer
Monterey is available through the Apple App Store. Click on Get located at the top right, and it will open the Software Update System preference. tap on download button. The download may take some time.
But after the download is complete and the installer is running, do it Not tap on Complete button. Exit the installer by pressing Command-Q. Then go to the Applications folder and you will find the “Install macOS Monterey” application. You must have the app there to create a bootable drive.
Use Terminal to create a bootable macOS Big Sur installation drive
1. Connect the external drive to your Mac. In this instructable, I use Untitled as the name of the external drive. If your drive is named something else, you need to change Untitled for your drive name.
2. Launch the terminal. It is located in the Applications > Utilities folder.
4. Return to Terminal and paste the copied code into the prompt. Remember to change Untitled for your drive name. Journalism Returns.
5. The terminal may ask for your password. Enter it and press Returns.
6. Terminal will warn you that the external drive must be erased. To continue, type Y at the prompt and press Returns.
7. An alert may appear asking for permission for the party to access the removable drive. click Yes.
8. You will see that Terminal scans your drive and then copies the installer file to your drive. This will take a few minutes.
7. After copying, the terminal is done. You should see Terminal display a message that the drive is ready for use.
How to boot from the installation drive
1. With the external drive connected to the power supply:
Intel Mac: Reboot/turn on your Mac and hold down the Option key on your keyboard during the boot process.
Apple silicon Mac: Reboot/turn on your Mac and hold down the Mac’s power button during the boot process.
2. The startup manager should appear. Select your external drive. It should appear as “Install macOS Monterey”.
3. Your Mac will boot into recovery mode and the installer will launch automatically. You can proceed with the installation from here. If you want to erase the drive first, exit the installer and run Disk Utility from the recovery menu. You can then erase the drive, then go back to the recovery menu and install macOS Monterey.
If your Mac won’t boot from the installer
Macs with the T2 security chip (Intel Macs manufactured since 2018) may not allow you to boot from the macOS Monterey installer. (Here’s a list of Macs with T2.) To fix this, there’s a setting in Startup Security that needs to be modified. Heres how to do it.
1. Boot into recovery mode by pressing Command + R while your Mac is booting up.
2. A list of users will appear. You need to select an account whose password you know.
3. When your Mac finishes booting up, select File Services menu, then select startup security tool.
4. You may be asked to authenticate. Enters macOS password, then choose the administrator account and enter the password.
5. After launching the application, find the “External Boot” section at the bottom of the window and select “Allow booting from external media”.
6. Quit the application and restart your Mac. You can try to boot from the installation drive as detailed in the instructions above.
Roman has covered technology since the early 1990s. He started his career at MacUser, working in MacAddict and Mac | Life and TechTV.