Creating a bootable OS X USB flash install drive is a great way to facilitate a clean installation of Mac OS X.
This will work for following versions of OS X:
- OS X 10.9 – Mavericks
- OS X 10.10 – Yosemite
- OS X 10.11 – El Capitan
Before you start, you’ll need a USB 2.0 or USB 3.0 flash drive with at least 8GB of storage available. A USB-C flash drive might be better choice if you’re are a new MacBook user.
- Open Disk Utility and format USB flash drive as Mac OS Extended.
- Launch the App Store on your Mac.
- Search for “OS X El Capitan” (or the current version of OS X, if different).
- Click “Download” or “Get”.
- If you have previously downloaded this file, you may find it in the “Purchased” tab.
- After the downloading process is complete, exit the App Store. The installation window should appear momentarily.
- Click the “Install OS X El Capitan” menu at the top left of the screen, and select “Quit Install OS X.“
- Insert your USB drive into your Mac’s USB port.
- Note the name of your USB drive – it should appear on your desktop.
- Launch Terminal.
You can either use Spotlight Search or navigate to “Applications / Utilities” and double click the Terminal icon to launch Terminal.
- In Terminal, type one of the following commands, depending on your version of OS X. (The name of OS, is the one you want to install on the USB flash drive. Not that of your Mac’s system). These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you’re using. If it has a different name, replace “MyVolume” accordingly.
- After correctly entering the command with the name of your USB drive, press the [return] key.
- Enter your Mac’s user password.
- Your password will not be displayed, but it is there.
- Press [return].
- Check the name and path of your USB key. If it looks correct, press the [Y] key, then press [return].
The bootable drive creation will begin. Please wait until the process completes.
- When Terminal indicates the process is “Done,” the creation of your bootable drive has succeeded.
To boot any Mac from your USB drive, first power it off and then press and hold the [option]or [alt] (⌥) key while turning it back on.
If you get the following error when trying to reinstall OS X:
“OS X could not be installed on your computer. No packages were eligible for install. Contact the software manufacturer for assistance. Quit the installer to restart your computer and try again. “
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