2020 MacBook Air - unable to factory reset to install new MacOS

Not enough space to download and install?

The somewhat tortured workaround is to create a Time Machine backup, erase the Mac, and then boot Recovery using the key chord that offers to install the latest macOS version compatible with that Mac.

When it finishes, migrate your User Account from the TM backup.

If you need more explicit instructions by all means write back, but create that Time Machine backup first. That alone might free enough space to accomplish the upgrade. Besides, after you delete files and empty the Trash it takes a while for the Finder to calculate and release space previously occupied by those files. The generally accepted amount of time is the better part of a day.

Links:

Back up your files with Time Machine on Mac - Apple Support

About macOS Recovery - Apple Support

To install the latest macOS version compatible with that Mac refer to this excerpt from Use macOS Recovery on an Intel-based Mac - Apple Support:

• Option-Command-R: Start up from macOS Recovery over the internet. Use this key combination to reinstall macOS and upgrade to the latest version of macOS that’s compatible with your Mac.

sarona20 wrote:

Hi, thanks for your comments! I want to skip the time machine backup and go straight to reset factory and install new MacOS.

There are 2 very different MacBook Air computers from 2020

One Is an Intel Computer and the other is a M1 Apple Silicon computer

Before we can help with your request, you will have to identify Which One is your Computer

Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

Please post back wit that specific information

On the Off Chance this is an Apple Silicon or the Apple T2 Security Chip computer

Use Erase All Content and Settings

It will Not Touch the Operating System itself

If macOS 11 Big Sur is installed.

it will still be installed after following the information in above link

It will remove your User Account and ALL that is in your account

Meaning, Applications, Setting, Photos, Music, Videos, Podcasts and Yes Documents

In that case follow my instructions but omit the steps that describe creating and restoring a Time Machine backup.