But they’re also what you do if something really bad happens to the copy of OS X that you boot your Mac from, or if the version of OS X on your Mac is earlier than 10.10 El Capitan. You don’t want to reinstall OS X if something easier can correct the problem.If you sell or give away your MacThe following instructions do triple duty: Of course they’re what you do to install OS X for the first time on a Mac or a freshly formatted hard or solid-state disk. If nothing else fixes your Mac, reinstalling OS X could well be your final option before invasive surgery (that is, trundling your Mac to a repair shop).
If you’re thinking about reinstalling because something has gone wrong with your Mac, know that an OS X reinstallation should be your last resort.
