Thanks Cory do I need to install Big S ? checking the model identifier it is MacBook Air 7.2
So the spec should support Monterey. Without having to download via system Preferences again
I will have todo that after tomorrow again; when Idid that today it failed
I would like to emphasize Cory’s point regarding the Time Machine backup. In fact, at least two will be better. Or to make restores faster, a clone (I’m partial to Carbon Copy Cloner) to an external drive will be great.
Your internal drive is probably HFS+ formatted since it came with Yosemite loaded, correct? HFS+ does not work well with Monterey, and the version of Disk Utility that comes with Catalina has problems. I recommend, after securing your backups, that you erase your internal drive from within Recovery and format it as APFS (default, no encryption), after which Recovery should offer to install the current version of macOS 12. You can subsequently migrate your existing data from your backup. Finally, you can turn on encryption from Systems Preferences (File Vault).