Windows 10 upgraded from Windows 8.1
Office 2016
Dell XPS 18
I cannot open Word documents that I download. I can open Word documents that I create on my computer. I have tried suggestions including updating Word (it was up to date), Open and Repair and Recover Text from any File. When I try to open the documents,
I receive this message:

I run an administrator account, and the computer has a huge amount of free memory and disk space. I can open the documents in WordPad, but they look corrupted. This has happened with multiple Word documents from different trusted sources. I am attempting
to open the files after saving them to the hard drive. The problem started immediately after the January 29 update.
Should you have a solution, it needs to be possible to do it without a working Start menu or Search function, a problem created by an earlier update that I posted to a different Forum without any luck. If I need to go to Windows Update for the solution,
please tell me how to get there without a Start menu or Search function.