iMac 27-inch Late 2012 - Deleted everything by accident: Mac partition AND recovery

Question

iMac 27-inch Late 2012 - Deleted everything by accident: Mac partition AND recovery

Hello all,

I was trying to install Bootcamp on my iMac 27inch Late 2012, and everything was successful until I got to the Windows Installation Setup after restarting the computer. It gave me the error that the disk format for the BOOTCAMP drive was MBR but Windows could only be installed on GPT disks. I researched this and thought I had found a fix by formatting the Bootcamp partition, and I had done so. Afterwards, just to check if it still worked, I restarted the iMac and pressed Alt. Usually, when I do this, it shows the boot-order screen, and it shows Macintosh HD and Recovery, along with the Windows and EFI Boot partition.

NOW, however, the Macintosh HD and Recovery drives do not show up, and I fear that I may have accidentally formatted the ENTIRE drive. The only boot options that show up are Windows and EFI Boot.

How do I fix this problem and restore MacOS? For now all I want to do is restore the OS and the recovery mode.

I originally had MacOS Mojave on a 1TB hard drive (not SSD).

Thanks

iMac, macOS Mojave (10.14), null

Posted on Oct 22, 2018 5:38 PM

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Answer 1

Best reply

Joseph_S.

Community Specialist

Oct 24, 2018 4:39 PM in response to ScientificCrisis

Hello ScientificCrisis,

After reviewing your post, it sounds like you formatted the disk and now you are not able to boot to macOS. If you want to recover macOS and if it is not available anymore, you can use internet recovery.

If you can't start up from macOS Recovery

Newer Mac computers and some older Mac computers automatically try to start up from macOS Recovery over the Internet when unable to start up from the built-in recovery system. When that happens, you see a spinning globe instead of an Apple logo during startup. To manually start up from macOS Recovery over the Internet, press and hold Option-Command-R or Shift-Option-Command-R at startup. Learn more about these key combinations.

If you still can't start up from macOS Recovery, you might need to reinstall macOS after starting up from another disk or volume, or by using a bootable installer.

About macOS Recovery

Thank you for using Apple Support Communities. Have a nice day.

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Answer 2

Oct 24, 2018 4:49 PM in response to Joseph_S.

Wait I've got a problem.

I was able to start up the recovery service, but when I go to choose the drive to install MacOS Mojave to (where is says "Select the disk where you want to install macOS"), my main hard drive doesn't show up. Is it because I had converted it into GPT format before? If so, do I need to convert it back to MBR?

Thanks

**EDIT: I fixed it by reformatting the drive as a GUID partition map.

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Answer 3

Oct 24, 2018 4:39 PM in response to Joseph_S.

Thanks so much!

I remember there was some command to start up a secondary recovery service but I couldn't remember what it was called.

Thanks again.

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iMac 27-inch Late 2012 - Deleted everything by accident: Mac partition AND recovery

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