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How to Install macOS High Sierra

What you need

  1. How to Install macOS High Sierra, How to Install macOS High Sierra: step 1, image 1 of 2 How to Install macOS High Sierra, How to Install macOS High Sierra: step 1, image 2 of 2
    • With the device powered off, disconnect any external hard drives and flash drives.

    • Plug in your macOS High Sierra bootable flash drive.

    • Hold down the [option] or [alt] (⌥) key on the keyboard and power on the device.

    • When you see the boot selection screen as shown, release the [option] key.

    • Use either the keyboard's arrow keys or the mouse to select "Install MacOS High Sierra." Press [enter] or click your selection with the mouse.

  2. How to Install macOS High Sierra: step 2, image 1 of 2 How to Install macOS High Sierra: step 2, image 2 of 2
    • Your Mac will begin copying the installation files from the flash drive. This may take up to 30 minutes.

    • Depending on the speed of your flash drive, it may look like progress has frozen, but it should resume if you continue to wait.

    • When prompted, select your language and press [enter], or click the arrow button.

  3. How to Install macOS High Sierra: step 3, image 1 of 2 How to Install macOS High Sierra: step 3, image 2 of 2
    • If you don't need to pre-configure your hard drive, skip to step 5. If you're not sure or if the drive is used, it's a good idea to pre-configure your hard drive.

    • Select "Disk Utility" from the menu and press [enter] or click the continue button.

  4. How to Install macOS High Sierra: step 4, image 1 of 3 How to Install macOS High Sierra: step 4, image 2 of 3 How to Install macOS High Sierra: step 4, image 3 of 3
    • Select your hard drive from the left column in Disk Utility.

    • It is most likely the uninitialized drive.

    • If you have multiple hard drives, make sure you select the correct one as the next step will wipe the selected drive clean.

    • Click the "Erase" button at the top of the window.

    • Choose a name for your drive (you can rename it later). Leave the scheme as GUID Partition Map.

    • If you are installing an SSD, choose the APFS format. If you are installing a mechanical drive or if your device doesn't officially support the newer OS, leave the format as Mac OS Extended (journaled)

    • Click "Erase." When the process completes, click "Done."

    • Exit the Disk Utility by clicking on the red X button on the top left corner of the window.

  5. How to Install macOS High Sierra: step 5, image 1 of 2 How to Install macOS High Sierra: step 5, image 2 of 2
    • Select "Reinstall macOS" from the menu and press [enter] or click "Continue."

  6. How to Install macOS High Sierra: step 6, image 1 of 3 How to Install macOS High Sierra: step 6, image 2 of 3 How to Install macOS High Sierra: step 6, image 3 of 3
    • Read through the license agreement.

    • Click "Agree" to accept the license agreement.

    • Your Mac will now install macOS High Sierra. Be patient and wait for it to complete.

    • Once the install is complete, the device will restart itself.

Conclusion

High Sierra should now be freshly installed! Enjoy!

619 other people completed this guide.

Arthur Shi

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74 Comments

I replace Toshiba MK1231Gal dard disk based on instruction on yutube http://www.youtube.com/watch?feature=pla...!

the problem is that when I try to install osx, I cant format the disk

I got notice input, output error, when try to make a partition or try anything with disk utility

I own MacBook air 1237

Iztok - Reply

I replace Toshiba MK1231Gal dard disk based on instruction on yutube http://www.youtube.com/watch?feature=pla...!

the problem is that when I try to install osx, I cant format the disk

I got notice input, output error, when try to make a partition or try anything with disk utility

I own MacBook air 1237

Iztok - Reply

yes, me too...did you get it fix? please share how.

jay zee -

Use disk utilities from the Mac OS installer to format the new drive in a Mac format. Then install the Mac OS. New drive won’t show up in the installer until it’s Mac format.

littleduckltd -

DDD in this case

dard disk

Ben Capehart -

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