If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track.

There are a number of possible explanations for why verification codes don't always arrive. Read through the list of the most common causes, and see if any of them apply to you, or use our troubleshooter to help guide you.

If you want to collaborate with them in Teams, you can add them as a guest. Guests have fewer capabilities than team members or team owners, but there's still a lot they can do. For a deeper look, see Guest capabilities in Teams. Note: You must be a team owner to add a guest in Teams.