How can I recover macOS Catalina after accidentally erasing internal data in Disk Utility?

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How can I recover macOS Catalina after accidentally erasing internal data in Disk Utility?

So when I launch recovery mode and look at my disk utility after I erased the internal data (I think that’s what I erased). When disk utility is opened I only see the MacOS base system is that normal?

My friend could be wrong but he said I might have deleted the operating system on accident, but we’re not sure. If I did can I restore it?

Note: I have tried to restore MacOS Catalina, but yesterday it switched to High Sierra. High Sierra is worse than Catalina so I’m at a loss.

My attempts to restore MacOS haven’t really worked. Does anyone have any suggestions or next steps I should take in order to resolve this issue?

[Re-Titled by Moderator]

Posted on Mar 24, 2025 10:57 AM

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Answer 1

Mar 24, 2025 12:25 PM in response to Nhicks333

Download the macOS 10.15 Catalina installer here:

https://itunes.apple.com/us/app/macos-catalina/id1466841314

The download will place the "Install macOS Catalina" app in the Applications folder.

It may launch automatically after the download completes. If not, double-click the installer to begin the upgrade process.

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Answer 2

Mar 24, 2025 11:51 AM in response to Nhicks333

MacOS Base System is the stripped-down simple macOS used to run Recovery and Installer. it is usually seen on a 2GB drive that is actually a Disk Image, which means it was pulled from the Mac's ROM.

Modern Macs, especially 2018 models and later, put part of the firmware on the beginning of the drive. If you do not follow the "approved method" you can brick your Mac.

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How can I recover macOS Catalina after accidentally erasing internal data in Disk Utility?