Can't install, help anyone?

oatman13

macrumors regular
Feb 14, 2013
228
60
I have an iMac 21.5, 2017, 1tb ssd drive. I've never had an issue installing an OSX until this install. Does anybody have an answer that doesn't require me to formatt my hd? I left an image.
Your drive was formatted with a legacy MBR, a GUID partition type is a requirement to run macOS.
You'll need to erase your drive and perform a clean install.
 

Howard2k

macrumors 68030
Mar 10, 2016
2,900
2,158
Your drive was formatted with a legacy MBR, a GUID partition type is a requirement to run macOS.
You'll need to erase your drive and perform a clean install.
Does High Sierra support booting from an MBR drive?
 

Rbfinch570

macrumors newbie
Original poster
Jul 22, 2017
26
7
Crap. I have to completly whip my drive? Is there something special I have to do when I format the drive?
 

oatman13

macrumors regular
Feb 14, 2013
228
60
Crap. I have to completly whip my drive? Is there something special I have to do when I format the drive?
Try to back up first, do you have an external drive or a Time Capsule? If so you should back up to it with Time Machine.

Afterwards Boot by holding CMD+OPT+R after hitting the power button. This will boot you to the Mojave RecoveryOS. From there open Disk Utility. GO to the menu bar at the top and under "View" select "Show All Devices".

You will see a section on the left that says "Internal"; select the top-level drive, then click "Erase" button on the top-middle of disk utility. In the drop down name your drive: "Macintosh HD", select APFS, make sure the scheme is "GUID Partition Map". Click Erase.
Then Close Disk Utility.

After you close Disk Utility select the "Install macOS" option (should have the Mojave icon). Begin the installation (will take a while since it has to download the installer), and you are good to go.

After installation, during setup you can restore from time machine backup if you backed up.
 
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