Does updating mac os delete everything
So Apple has recently started automatically downloading the latest version of Mac OS onto most people's computers.
With the latest version of Mac OS, Sierra, Apple is automatically downloading the major update, which takes up about 5GB of space.
Apple also releases system updates that keep your Mac secure and stable.
When a new major version of OS X is released, you can download the upgrade for free from the App Store.
Published April 11th, 2013 at AM EST , modified January 2nd, 2016 at PM EST For whatever reason, you have decided that you want to reinstall the system from scratch, restoring your machine to an “out-of-the-box” state.
Further, if you do the job wrong, whatever problem you’re trying to solve may not even be solved. Before erasing the hard drive, make sure you have a minimum of two completely separate backups, on completely separate media, and preferably made with two different backup programs.Installing from older system disks can leave you with a somewhat outdated system, so you’ll want to be sure that you take care of bringing it back up to speed.If you reinstalled Mac OS X 10.7 or 10.8, this should not be an issue, since you will have downloaded the most up-to-date version.Still, it can’t hurt to go ahead and check for updates anyway.Once your clean, new system is up and running and fully updated, work on getting all the settings back to the way you like them.