How to do a clean install of macOS High Sierra

“Downloading and installing a new OS gives you the opportunity to do some major house cleaning if you so desire,” Luke Filipowicz and Lory Gil write for iMore. “If you feel like you’d like a fresh start with macOS High Sierra, you can always opt to do a clean install.”

“This process will erase whichever OS you’re currently using from your hard drive entirely,” Filipowicz and Gil write. “That means any files, programs, or documents you have will be deleted. To save your files, put them on an external hard drive or a cloud-based program like Dropbox, OneDrive, or iCloud. If you don’t save these important files off your computer, you will lose them.”

“Before you erase your current operating system, download macOS High Sierra from the Mac App Store,” Filipowicz and Gil write. “You’ll need a copy of macOS High Sierra to perform a clean install later on. If you don’t create a bootable drive for macOS High Sierra, you’ll have to install an older Mac operating system first and then upgrade to macOS High Sierra afterward.”

The full how to here.

MacDailyNews Take: It’s always nice to have a fresh Mac performing at its best following a clean install!


    1. You didn’t read the article did you? Pretty obvious because the article is excellent and very helpful for anyone who needs to do it.

      I would be willing to bet that if asked to do a clean install of any recent Mac OS, the vast majority of Mac users would not know how. Apple does not make it obvious how to do a clean instllation safely, Apple’s own literature on the subject is quite poor. The superficial little page Apple does offer at doesn’t explain all the installation options or the nuances between them. One could waste hours on Apple’s poorly moderated discussion boards to find complete answers to anything. APPLE HAS OUTSOURCED ITS SUPPORT FUNCTIONS TO USERS AND 3RD PARTY MEDIA BECAUSE THEY DON’T CARE ANYMORE.

      If you are a highly competent MacOS expert who knows all things about the Mac, then fine. The other 99% of users are not.

  1. High Sierra will be my last macOS clean install. The huge effort to reset whole workflow after the process is not worth it due to risk of losing plugins, authorizations, presets, configurations, archives and so. Clean install would have made sense in the past but now, after assuming one for APFS formating on High Sierra, I realize it’s too time consuming and troublesome. I understand the beauty of a clean install which I have made several times. But after High Sierra, not any more.

    1. You say that now, but you may change your mind.

      There was a time when I never did clean installs, I would buy a new Mac and transfer what I needed from the old machine using Target disc mode. Every 3-4 years, a new Mac had twice the capabilities of the prior one.

      Today Apple doesn’t even attempt to give users good reasons to buy new Mac hardware, Apple has let its own hardware performance fall dramatically behind Windows machines, which reinforces the decision of software makers to port their premium apps only to Windows. If that is the future reality, multi-OS Hackintoshes are a very likely choice for us. Clean OS installs may be necessary when we sell off the old Mac Pros.

  2. I’m too impatient to copy files back across. My strategy is this. Your spend a little more time setting things back up, but nearly no time for copying data across, and you have the opportunity to rebuild or preserve user accounts.

    • Make an installation USB and boot into it
    • Mount your destination volume with Disk Utility
    • Open Terminal and navigate to the root of the destination volume
    • Make a directory called “Old”, etc
    • Move everything into this created directory
    • Run your clean install
    • Copy our what you need from your old installation (eg user accounts, preferences, apps)
    • When you’re sure you’ve got everything you need, delete the old files.

Reader Feedback

This site uses Akismet to reduce spam. Learn how your comment data is processed.