Keep holding it until you see the Utilities menu
How to Reinstall macOS Catalina from USB Driveīefore installing macOS Big Sur beta, did you make a Time Machine backup of your Mac running macOS Catalina? If yes, you can restore all files and data from it after downgrading.How to Reinstall macOS Catalina from Internet.How to Downgrade macOS Big Sur Beta to macOS Catalina Ready To Begin?: If it is a MacBook, plug it to power as it requires significant energy, and the process is lengthy.Take a moment to see how to create a bootable macOS USB Drive.
However, then you put it on a pen drive, and thus the actual installation is quick. And for the second method also require the internet to download the OS. For the first method, high-speed internet is recommended as it will download the full macOS (around 8+ GB). Two Methods: You can install macOS Catalina using the internet or a bootable macOS Catalina USB drive.Understand The Whole Process: Downgrading involves Backup (optional but recommended) → Erasing macOS Big Sur → Installing macOS Catalina → Restoring from Time Machine backup (if you have a macOS Catalina backup).Let me show you how to downgrade from macOS Big Sur beta to Catalina. But now, if you are looking to go back to macOS Catalina for any reason, it is possible. You may have installed it to check out the new features. MacOS 11 Big Sur is still in the beta version.