How to create a bootable installation program for macOS

If you are a Mac user who wants to perform a clean installation of macOS or needs a USB for troubleshooting purposes, a bootable installation program is the way to go. With a bootable installer, you can easily install macOS on any compatible Mac without relying on the App Store or an already installed operating system. Here’s a step-by-step guide to help you a bootable installation program for macOS using either a USB drive or an external hard drive.

1. Prepare Your Equipment:
Before you begin, make sure you have a Mac device running on macOS Catalina, Mojave, High Sierra, or an older version like El Capitan or Yosemite. You will also need a USB drive or an external hard drive with at least 12GB of storage capacity. If you have important data on the drive, make sure to back it up as this process will erase everything.

2. Download macOS Installer:
To create a bootable installation program, you first need to download the macOS Installer. Open the App Store on your Mac and search for the specific version of macOS you want to install (e.g., macOS Big Sur). Once found, click on the “Get” button to start the download.

3. Format the Drive:
Connect the USB drive or external hard drive to your Mac. Open the “Disk Utility” app, which you can find in the Applications/Utilities folder. Select your drive from the sidebar and click on the “Erase” tab. Choose a name for your drive and select either “Mac OS Extended (Journaled)” or “APFS” as the format. Finally, click on the “Erase” button to format the drive.

4. Create the Bootable Installer:
Open the Terminal app, which can also be found in the Applications/Utilities folder. Type the following command, replacing ‘Name_of_Your_Drive’ with the actual name you chose for your USB drive:

sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia –volume /Volumes/Name_of_Your_Drive

Press the ‘Return’ key and enter your admin password when prompted. The Terminal will begin creating the bootable installer, which may take a while depending on the size of the macOS Installer and the speed of your drive.

5. Use the Bootable Installer:
Once the process is complete, you will see the message ‘Install media now available.’ Your bootable installation program for macOS is ready to use. Restart your Mac, holding down the Option/Alt key, until the Startup Manager appears. Select the bootable installer drive and click the ‘Enter’ key. The Mac will then boot from the USB drive or external hard drive, allowing you to install or troubleshoot macOS.

Creating a bootable installation program for macOS gives you more control and flexibility over your Mac’s operating system. It ensures that you always have a reliable way to reinstall macOS or perform advanced troubleshooting whenever needed. Just remember to keep your bootable installer drive safe, update it with new macOS versions periodically, and be cautious when using it to avoid accidental system reinstallation.