How to boot mac from USB: Best Step-by-Step Guide

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By Emma Wilson

Have you ever thought How to boot mac from USB drive on a modern machine? This technical time travel is facilitated by the building of a bootable USB device. This comprehensive tutorial of How to boot mac from USB will guide you through the entire procedure, ensuring that your current Mac is transformed into a time machine.


Taking up the challenge to make a bootable USB stick for an outdated Mac operating system requires a trip back in memory. This How to boot mac from USB guide will serve as a guide on this interesting journey, helping you to restore classic software. Follow these instructions of How to boot mac from USB guide for an old Mac operating system on a current Mac:

Note: This How to boot mac from USB tutorial assumes you have a modern Mac running a macOS version that supports Disk Utility and access to the internet to download the macOS installer.


  • A blank USB drive with at least 8 or 16 GB of storage space.
  • Disk Utility provides access to a modern Mac.
  • Internet access is required to download the macOS installation.

Step 1: Prepare the USB Drive

  • Connect your USB drive to your Mac.
  • Open the Disk Utility application. It is found within the Applications folder in the Utilities folder.
  • Go to the “View” option in the Disk Utility app and select “Show All Devices.”
  • Select the top level of your USB drive from the left sidebar.
  • Select the “Erase” option.
  • Give your USB drive a name in the “Name” field.
  • In the “Format” drop-down menu, choose “Mac OS Extended (Journaled).”
  • In the “Scheme” drop-down option, choose “GUID Partition Map.”
  • To format the USB drive, click the “Erase” option.
  • Close the Disk Utility software after erasing.

Step 2: Download the macOS Installer

  • Open your web browser and go to the Apple support page for downloading your required Mac operating system.
  • Download the macOS installer that matches your needs. Some older macOS versions can be downloaded directly from this page.

Step 3: Extract the macOS Installer

  • In your “Downloads” folder, you will find a DMG file with the macOS installer. Open it.
  • Inside the DMG file, you’ll find Apple’s installer in zip or package format.

Option A: Extracting with Package Installer 3. If the installer is in package format, simply double-click it and install it onto your Mac. This will place the installer in your Applications folder.

Option B: Extracting with Archive Software 3. If you encounter errors with the package installer, you can use an archive software like an RAR extractor to extract the installer.

  • Right-click on the package file and extract the macOS installer.

Step 4: Prepare the USB Drive

  • After extracting the installer, navigate to the extracted folder.
  • Locate the “install OS” package file, right-click it, and choose “Show Package Contents.”
  • Find the “install ESD” file within and double-click it to mount it.
  • You might need to reveal hidden files by pressing Command + Shift + Period (.) simultaneously.
  • Locate and mount the “base system DMG” file.
  • Reopen the Disk Utility application.

Step 5: Restore the USB Drive

  • Right-click on your USB drive in Disk Utility.
  • Select “Restore.”
  • From the “Restore” drop-down menu, choose “OSX base system.”
  • Click the “Restore” button. This process will not take long.
  • Click “Done” and close Disk Utility.

Step 6: Add Additional Files

  • Go to the “install ESD” folder of your installer.
  • Copy the “base system.dmg” and “base system.checklist” files to your USB drive.
  • Navigate to the “system” folder on your USB drive.
  • Inside the “system” folder, open the “installation” folder.
  • Delete the “packages” shortcut.
  • Go back to your “install ESD” folder and copy the “packages” folder into the same location on your USB drive.

Step 7: Final Step (How to boot mac from USB)

  • Go to your USB drive.
  • Right-click on “install Mac OS Sierra” and select “Show Package Contents.”
  • Navigate to the “Contents” folder and then the “Resources” folder.
  • Locate the “install assistant” icon file, copy it, and paste it onto your USB drive.
  • Rename the copied file to “volumeicon.icns” (type the exact name).

How to boot mac from USB tutorial is now complete. It can be used to install macOS Sierra on compatible Macs. If you find this procedure challenging, you could try TinkerTool System, which can make a bootable USB stick without using the Terminal. (How to boot mac from USB)…..

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