iMac reinstallation: 'Could not create a preboot volume'

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Level 1

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iMac reinstallation: 'Could not create a preboot volume'

My iMac (6 years old, bought in 2019) kept getting stuck during startup (with the Apple logo and a half-filled progress bar on the screen), so I deleted the hard drive and wanted to re-install the operating system. However, this failed because the reboot did not work – error message: ‘Could not create a preboot volume for APFS install’. When going into the recovery system, I get offered macOS Sequoia to be re-installed, which should be compartible with the iMac (I think) - or should I try an older system first? If yes, how can I do this? Or should I try an external disk for prebooting? If yes, how can I do this? Sorry, I don't know much about this stuff...

Cheers, Janet

iMac 21.5″, macOS 14.7

Posted on Dec 5, 2025 12:17 AM

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Answer 1

HWTech

Level 9

68,444 points

Dec 5, 2025 8:24 PM in response to jankar72

Out of curiosity, did you try to boot into Safe Mode before deciding to reinstall macOS? Or run Disk Utility First Aid while booted into recovery mode?

Very likely the internal HD is failing, but it could also be a file system issue. While booted into Internet Recovery Mode (Command + Option + R), launch Disk Utility and erase the whole physical drive in order to create a new partition & file system. Within Disk Utility you may need to click "View" and select "Show All Devices" before the physical drive appears on the left pane of Disk Utility. If your iMac uses a Fusion Drive, then just erase the Fusion Drive item instead.

Keep in mind erasing the drive or Fusion Drive will destroy all data on that drive. Make sure to have a good backup before erasing the drive or you will lose your data.

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