BigSur on a new iMac

[michaelGR]

New iMac came with BigSur loaded on it. Can I get rid of it? If so How? I would prefer Mojave. Boot Security Settings in Recovery mode seems to be the right place to start.

 

[usagora]

Maybe these will help?

How to Downgrade macOS Big Sur to Catalina or Mojave

Did you update to macOS Big Sur but now wish you hadn’t? Are you no longer interested in using macOS Big Sur on your Mac? Perhaps you installed it to try out all new features and changes, but…

osxdaily.com

How to downgrade macOS update: Rollback Sequoia to Sonoma

Regret updating to macOS Sequoia? Here's how to uninstall Sequoia and revert back to Sonoma.

www.macworld.co.uk

 

[coso]

No, previous macOS versions are not compiled for M1. You can only run Big Sur and later. Better return it and get an intel. Personally after 13 years of macOS Big Sur is BY FAR my preferred os system