Macos High Sierra Bootable Usb Flash Drive Installer

Creating a bootable macOS High Sierra USB installer

Want to install or reinstall macOS High Sierra but don't have the installation media? Creating a bootable USB installer is the solution. This guide walks you through the process, ensuring a smooth and successful installation. This method is particularly useful for troubleshooting system issues or upgrading older Macs.

What you'll need:

• A macOS High Sierra installer (.dmg file). You can obtain this from the App Store (if still available) or from a legitimate source.
• A USB flash drive with at least 8GB of storage. Important: All data on the USB drive will be erased during the process, so back up any important files beforehand.
• A Mac running macOS High Sierra or later.

Step-by-Step Guide:

1. Prepare your USB drive

Before you begin, it’s crucial to back up any important data on your USB drive. The process will completely erase the drive. Next, identify your USB drive. Open Disk Utility (found in /Applications/Utilities/). In the sidebar, locate your USB drive. Note its name – you'll need this later.

2. Download the macOS High Sierra installer

If you don't already have the macOS High Sierra installer, download it from a legitimate source. Once downloaded, locate the .dmg file.

3. Open Terminal and run the command

Open the Terminal application (found in /Applications/Utilities/). You will use the createinstallmedia command. This command requires administrator privileges, so you'll need to authenticate. The command below assumes your USB drive is named "MyUSB" and the High Sierra installer is located at /path/to/Install macOS High Sierra.app. Replace these placeholders with your actual drive name and installer path.

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB --applicationpath /Applications/Install\ macOS\ High\ Sierra.app --nointeraction

Explanation of the command:

• sudo: Executes the command with administrator privileges.
• /Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia: This is the path to the utility that creates the bootable installer. The spaces in the application name require escaping with backslashes (\).
• --volume /Volumes/MyUSB: Specifies the volume (your USB drive) – replace MyUSB with the actual name of your USB drive.
• --applicationpath /Applications/Install macOS High Sierra.app: Specifies the path to your macOS High Sierra installer .dmg file. Again, adjust the path if needed.
• --nointeraction: Runs the command without user interaction, speeding up the process.

4. Wait for the process to complete

The process may take some time, depending on your computer's speed and the size of your USB drive. Do not interrupt the process. Once complete, the terminal will display a confirmation message.

5. Verify the bootable drive

After the process is finished, eject your USB drive and try booting from it. Restart your Mac and hold down the Option key immediately after powering on. You should see your USB drive listed as a bootable option.

Troubleshooting:

• Incorrect drive name: Double-check the name of your USB drive in Disk Utility. A simple typo will cause the command to fail.
• Installer file location: Ensure you are using the correct path to your macOS High Sierra installer application.
• Insufficient permissions: Make sure you have administrator privileges.
• Drive format: The USB drive must be properly formatted before running the command.

Creating a bootable macOS High Sierra USB installer empowers you to troubleshoot system problems and perform clean installations efficiently. By carefully following these steps, you can successfully create your bootable installer and ensure a smooth installation experience. Remember to always back up your data before starting the process.