How to upgrade to High Sierra (fresh install)

Discussion in 'Mac Basics and Help' started by raymanh, Sep 14, 2017.

  1. raymanh macrumors member

    Aug 27, 2017
    I've got a 2016 MBP and will want to do a complete fresh install of High Sierra when it comes out on the 25th. I'll take everything I need off the Mac prior to installing High Sierra. My question is how can I install it completely fresh?

    Will I have to go through the method of holding cmd-r on restart, erasing the SSD and installing High Sierra (I don't know if thats possible as I thought that it only reinstalls the OS edition that came with the Mac which is Sierra in my case). Or, when downloading from iTunes, will it give me the option of a completely fresh install?

    Also, I am aware of having to sign out of iCloud, iMessages and iTunes. Will that then automatically delete my Mac off my iCloud account, ready to re-add it when I fresh install High Sierra?

    Thank you.
  2. Audit13 macrumors 601


    Apr 19, 2017
    Toronto, Ontario, Canada
    I have never seen a "fresh" install option for El Capitan or Sierra.

    To create an installer, try this: go to app store with a machine running Sierra, select the upgrade option, download the file which should be around 4 gb, don't install, use these instructions to create a usb installer for future use:

    My suggestion is based on the assumption that high Sierra will be pushed out the same way as Sierra and El Capitan and the installer instructions apply to High Sierra.

    Unfortunately, you'll still need to boot from the High Sierra installer, erase, install.
  3. Fishrrman, Sep 14, 2017
    Last edited: Sep 14, 2017

    Fishrrman macrumors P6


    Feb 20, 2009
    Best way, in my opinion:

    1. Install High Sierra installer on a USB flash drive (at least 16gb)
    2. Use either CarbonCopyCloner or SuperDuper to clone current contents of internal drive, creating a cloned backup copy.
    3. Boot from the cloned backup and re-initalize the internal drive.
    4. Shut down, then disconnect cloned backup
    5. REboot to the HSierra installer on the flash drive
    6. Do the installation
    7. When done, connect external cloned backup and reboot from new HiSierra on the internal drive
    8. At the appropriate moment, setup assistant will ask if you have applications, accounts and data to migrate. Assuming that you do, "aim" setup assistant at the cloned backup, select what you wish to bring over, and "let 'er go".
    9. When done, you should be able to log into your old account and be where you want to be.

    HOWEVER... IF something doesn't go as planned, YOU STILL HAVE THE CLONED BACKUP, which makes it easy-as-pie to "get back, get back, get back to where you once belonged..."
  4. Prizm4 macrumors newbie


    Sep 8, 2017
    I'm new to Mac and haven't done this before. Do the new versions of the OS give you an option to clean install during the installation process, or are clean installs an unofficial workaround?
  5. raymanh thread starter macrumors member

    Aug 27, 2017
    From what I've read you do this:

    1. Move all your files off onto an external hard drive.

    2. download high sierra from the App Store but don't install it yet.

    3. Plug in a USB drive and format it. Then put that high sierra file that you downloaded onto the USB properly (using the terminal commands)

    4. Sign out if iCloud and iMessage and sign out and deauthorise iTunes.

    5. Reboot holding option (I think) to get to the screen where you choose to boot via the laptop's SSD or the USB drive. Choose the USB drive.

    6. You'll then be in the installer window with the option of erasing your SSD to start afresh.

    7. Install and resign into everything and transfer your stuff back onto it.

    90% sure that's right for a fresh install. Let me know if otherwise.

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4 September 14, 2017