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Lost the administrator password for the iMac. Can't upgrade OS without it. How to recover or change?
iMac 21.5″, macOS 10.12
Here are the Apple Support articles on this topic:
https://support.apple.com/en-us/HT202860
https://support.apple.com/en-us/HT212190
macOS 10.12 is very old, and you might end up deleting AppleSetupDone and recreating an admin login:
https://discussions.apple.com/thread/2001369
If the install is rubbish or was one you “took over”, maybe get a backup of your files, erase and reinstall a more current version, and restore your content..
Follow these instructions:
Lost the administrator password for my iMac, unable to upgrade OS. It's not the same as my Apple ID. How can I recover or change the password for the computer itself?
