Click Start, and then click Control Panel. Double-click Programs and Features. Click Microsoft 365, and then click Change. Select Quick Repair, and then click Repair.
What does Microsoft Quick repair do?
Quick Repair – Fixes most issues quickly, without the need for an internet connection, or, Online Repair – Fixes all issues, but takes a little longer and requires an internet connection throughout. You can select this option if you are still having problems after trying Quick Repair.