Locked macOS, can't reinstall High Sierra

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Locked macOS, can't reinstall High Sierra

can not reinstall operating system because of locked disk

I I am having similar problems as many others, but I don’t see or understand fully the various solutions offered on the forum as applicable to my situation.

My system: iMac 27”, mid 2010, last macOS— High Sierra, 10.13.6

I was intending to sell this iMac after wiping it & then reinstalling the OS. Everything went fine until I got to the screen which read: No connection to the internet. I forgot that the iMac had an ethernet port on the back, & that’s where I think things went wrong. I erased the OS X Base System, thinking I could use my install disc to reinstall the original Lion OS. Wrong. After that it always booted up to macOS utilities, where I repeatedly got OS X Base System is locked when I tried to reinstall High Sierra. I have tried several Mac startup key combinations, but all boot up to macOS utilities. A circular firing squad. I don’t know how to proceed at this point. The Apple Store support is not really worth it as my 2010 iMac is probably too old to be sold for more than the support costs. Somebody can probably use this iMac.

Any practicable help would be greatly appreciated.

Posted on Dec 23, 2022 3:15 PM

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Answer 1

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Jack-19

Level 8

45,694 points

Dec 23, 2022 6:24 PM in response to chofat934

OK, thanks for running through those steps! What's in Disk Utility now is what you want to see; OS X Base System as a separate disk image under "Disk Images".

Now, select the top-level "ST31000528AS Media" drive, click Erase, and make sure this information matches:

Name: Macintosh HD
Format: Mac OS Extended (Journaled)
Scheme: GUID Partition Map

Click Erase, then quit Disk Utility, and reinstall macOS High Sierra.

Jack

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Answer 2

chofat934 Author

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6 points

Dec 23, 2022 7:50 PM in response to Jack-19

Thank you Jack!! You're a genius ! They should give you a raise! My old iMac is now reinstalled & ready to go back into circulation. I can't thank you enough. Have a great holiday & prosperous new year. Live long & Prosper!

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Answer 3

chofat934 Author

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Dec 23, 2022 4:06 PM in response to chofat934

Just received ocloud pics:

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Answer 4

chofat934 Author

Level 1

6 points

Dec 23, 2022 3:47 PM in response to Jack-19

Thanks for your fast response. it's going to take a few minutes for iCloud to transfer it to my macAir. The picture says the OS X Base System & above it: ST31000528AS MEDIA, SATA INTERNAL physical disk, GUID partition map. also S.M.A.R.T. status : verified; device: disc0

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Answer 5

Jack-19

Level 8

45,694 points

Dec 23, 2022 5:05 PM in response to chofat934

Is this new screenshot from Internet recovery (Command-Option-R)? Can you take a new photo of Disk Utility? Right now, these commands are trying to get your Mac in a state where you can reinstall macOS.

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Answer 6

Jack-19

Level 8

45,694 points

Dec 23, 2022 10:12 PM in response to MisJaxon

MisJaxon wrote:

I'm having the same issue, I'm running Sierra... I followed all these steps and right before it finishes I get an error that says it can't be completed. Can you tell me why that might be happening?

Hello!

What year is your iMac? Did you startup with Command-R, Option-Command-R, or Shift-Option-Command-R?

Jack

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Answer 7

chofat934 Author

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6 points

Dec 23, 2022 5:05 PM in response to Jack-19

can't reinstall High Sierra, OS X system locked

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Answer 8

chofat934 Author

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6 points

Dec 23, 2022 5:32 PM in response to Jack-19

Locked macOS, can't reinstall High Sierra

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Answer 9

Jack-19

Level 8

45,694 points

Dec 23, 2022 4:16 PM in response to chofat934

Thanks for the screenshots!

Try this:

Shut down your Mac.
Turn it on, and immediately press and hold Command-Option-R.
If successful, take a new screenshot of Disk Utility.

Jack

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Answer 10

chofat934 Author

Level 1

6 points

Dec 23, 2022 6:07 PM in response to Jack-19

Yes it is. The new pics I just sent you are low resolution. Sorry. They come from Disk utility. I'mreloading them with better resolution:

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Answer 11

Jack-19

Level 8

45,694 points

Dec 23, 2022 3:18 PM in response to chofat934

Hello!

In macOS Recovery, please go to Disk Utility, and select View > Show All Devices. Take a photo of this window, and upload it here.

Jack

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Answer 12

MisJaxon

Level 1

12 points

Dec 23, 2022 9:46 PM in response to Jack-19

I'm having the same issue, I'm running Sierra... I followed all these steps and right before it finishes I get an error that says it can't be completed. Can you tell me why that might be happening?

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Locked macOS, can't reinstall High Sierra

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