How to boot a Mac from a USB with the Option (⌥) key? The first thing to do before changing the hard disk or before installing the new OS is to prepare a USB stick with MacOS to reinstall the operating system on our Macbook. Do you know how to boot a Mac from a USB? Do you have an iMac or a Macbook Pro already with a few years under its belt and want to give it new life by installing a new solid hard drive SSD? Do you want to install Apple’s operating system from scratch on your Mac?
