Knowledge Base
Repairing Office 365 caused it to uninstall
If you're having problems with Microsoft 365 appications such as Word or Excel not opening properly then trying a Quick Repair is the first step in resolving the problem.
If this doesn't work then doing an Online Repair is the next option. But this causes Microsoft 365 to completely uninstall and reinstalling doesn't work.
Solution
1. Download and run the Microsoft 365 uninstall support tool from Microsoft website.
2. Under Option 2 select Download.
3. Once complete try reinstalling Microsoft Office 365.