This article explains how to fix startup problems with your Mac. The instructions apply to all macOS computers and laptops.

An additional user account with administrator privileges can help you troubleshoot issues with your Mac.

The purpose of a backup account is to have a pristine set of user files, extensions, and preferences to load at startup. This can often get your Mac working if your main user account is having issues, either at startup or while you’re using your Mac. Once your Mac is up and running, you’ll use a variety of methods to diagnose and repair the problem.

You do need to create the account before any problems arise, so make sure you put this task at the top of your to-do list.