
Note: Reformatting the drive will erase all data on the drive, so you should copy any data you want off the drive prior to formatting. Not sure what version you are using? Click here to determine your version of macOS. This article applies to the following versions of macOS: The following is not an exhaustive list of error messages, so you may not find your specific error here. Updated December 2019: Everything is up to date through macOS Catalina.This article covers some of the common error messages and questions you might encounter while using Disk Utility. If you have any more questions about reinstalling macOS on your Mac, let us know in the comments. How to set up and customize your Mac from scratch Questions? If you're starting from scratch, you'll need to set up your Mac from scratch. Your Mac will now go through the normal macOS installation process, eventually restarting.

Click on the drive on which you wish to install macOS.How to reinstall macOS while in Recovery mode

If you're running macOS High Sierra or later on a Mac with an SSD, your choices will be some form of APFS.


The first thing you'll want to do is make sure your Mac's startup disk is healthy. How to check your startup disk with Disk Utility in macOS Recovery mode Press Shift - Option - Command - R to install the version of macOS that came with your Mac, or the version closest to it that's still available.Press Options - Command - R to upgrade to the latest version of macOS that's compatible with your Mac.Press Command - R to install the latest version of macOS that was installed on your Mac without installing a later version.
