If you cannot open Microsoft Office program files, you can start Word, Excel, PowerPoint, Outlook, Publisher, Viso, etc, in Safe Mode in Windows 11/10.

When I delved deeper, I was directed to the Windows Store to find the association, but I could not locate the Excel app there for some reason. How can I reset this so my .XLS files open in Excel ...

Step 1: In Excel, open the document you want to secure with a password. Step 2: Click File, ... Windows 10 Professional users have a built-in encryption utility called BitLocker.