I used recovery mode to erase my hard drive and reinstall MacOS Big Sur (older MacBook Air). However, MacOS Mountain Lion installed, but I'm unable to get it to run and update. Many mistakes I suspect along the way, this is the short version. I have all my data saved, so no worries there. How do I start completely from scratch on my hard drive and reinstall Big Sur?
I have a second MacBook Air so I have that as a download resource.
MacBook Air
I understand you completely erased your Mac with the result that its original operating system (Mountain Lion) was reinstalled, but something went wrong with it.
Without knowing exactly what is not working it's difficult to speculate what went wrong, but here are the instructions for starting over from the beginning: Erase and reinstall macOS - Apple Support. Those instructions are for High Sierra, but they are the latest available instructions applicable to your older MacBook Air.
In Step 4 choose Mac OS Extended format. That is probably the only choice that will appear anyway.
Reinstall macOS in Step 6 should result in reinstalling Mountain Lion.
Once that's complete and working, please write back. Finally getting to Big Sur will involve an intermediate upgrade to El Capitan, so you might need additional help.
I understand you completely erased your Mac with the result that its original operating system (Mountain Lion) was reinstalled, but something went wrong with it.
Without knowing exactly what is not working it's difficult to speculate what went wrong, but here are the instructions for starting over from the beginning: Erase and reinstall macOS - Apple Support. Those instructions are for High Sierra, but they are the latest available instructions applicable to your older MacBook Air.
In Step 4 choose Mac OS Extended format. That is probably the only choice that will appear anyway.
Reinstall macOS in Step 6 should result in reinstalling Mountain Lion.
Once that's complete and working, please write back. Finally getting to Big Sur will involve an intermediate upgrade to El Capitan, so you might need additional help.
Need to start from scratch on my hard drive
