How to Install macOS from USB

Installing macOS from a USB drive is a straightforward process that requires some caution and attention to detail. In this article, we'll outline the steps necessary to clean install macOS Mojave from a USB flash drive.

Step 1: Get the DMG File

To start, you'll need to get the DMG file for your desired version of macOS. You can do this by going to the Mac App Store and looking in the Purchased section. If you already have the OS installed on that machine, it will appear there. Alternatively, you can search for a particular version in the store.

Step 2: Install and Launch DMG to USB Burning Utility

Once you have the DMG file, install and launch a DMG to USB burning utility such as UUByte DMG Editor. Insert a USB drive with at least 12GB of space (for macOS 10.14 Mojave, some require up to 16GB). Make sure to back up any important information already stored on the drive, as it will be formatted for the macOS installation.

Step 3: Import the macOS Installer and Burn to USB

Launch Disk Utility and select the appropriate USB drive. Set the format to Mac OS Extended (journaled) and the scheme, if required, to GUID Partition Map. Fill out the Name, Format, and Scheme fields, then click Erase and Done.

Step 4: Create Bootable Media

Now you'll need a disk authoring software that can write the DMG file with all relevant boot information to make it bootable. This step requires some care, as you can't create bootable media by just copying a DMG to a USB stick. You need the installation files, which will be deleted if the OS is installed.

Step 5: Boot from the Drive

Insert the USB drive and restart your Mac. Hold down the 'Option' (⌥) key while booting to select the USB drive as the boot device. If you cannot boot from the drive, you won't be able to proceed with the installation.

By following these steps, you can successfully install macOS Mojave from a USB flash drive. Remember to take your time and follow each step carefully to avoid any issues during the installation process.

How to install macos from usb