If you have downloaded Mac OS X latest version from the app store, it would be in. To perform this task, you will have to make a bootable USB Stick or Flash Drive, and we will tell you how. Boot from it, format your Mac’s Hard Disk/Flash Storage, and then reinstall OS X. If you are trying to make a fresh installation of OS X on your Mac or just want to Factory Reset MacBook Pro, MacBook Air or even iMac, the better way to do is make a bootable flash drive or USB Stick for Mac.
