Windows 10 keeps changing my default programs

None of the updates have anything to do with your personal files. As you would know if you bothered to study what the updates actually were.

Which you could simply by clicking on any one of them and seeing what they included:

RE-EDITED FOR CLARITY

But: This page will give you the contents of the most recent cumulative update:

https://support.microsoft.com/en-us/help/4089848/windows-10-update-kb4089848

AND this page will give you the contents of the one before that:

https://support.microsoft.com/en-us/help/4088776/windows-10-update-kb4088776

And here's one from last month: https://support.microsoft.com/en-us/help/4074592/windows-10-update-kb4074592

You get the idea, I'm sure. Nothing here is messing with your apps. You are free to spend the rest of the week reading up on all the updates, if you like. Just keep clicking the entries on the left side of the page.

There is, in these latter years of the second decade of the 21st Century , a belief (fostered by a certain President of the United States) that if you keep repeating inane and demonstrably false statements long enough they eventually become true.

This belief is ill-founded.

You are so obtuse. 

I am telling you the behavior on my computer - as is happening on others who have replied to this thread. When the effing icons change, the program changes. 

Forget about the .mp3s from WinZip for a moment. That was what I found to be the cause. Again - for the millionth time - i have not had the issue since I stopped using WinZip.

What you fail to realize is in your snarky responses is that the icons change; the default programs change; and the settings change.

A pdf icon will change to Edge; it will open with Edge; and the default program in setting will become Edge. Same with any video file that Microsoft has decided should be used with Movies and TV. I can go through all of my video files and change them to VLC viewer....and, again, if I extract mp3 files using WinZip - when they change, everything that I have changed from Microsoft's defaults will change.

[Mod Removed]

Its changing more than just the icons.  It is changing the actual program assignments.  This is a phenomena that has just recently started.  It has been going on for the past month or so.  I have not added any new programs during this period.  The only thing that may have changed is windows, through their mandatory updates.

I can start the program and then open the required file, but we have millions of files in a very elaborate and deep directory structure.  To open the program and then drill down to the file that I need to open, would be prohibitively time consuming.  I often need to access a hundred or more files in a single day.  It is much more efficient to work directly from the file manager and double click on the file I want to open.

Microsoft has done this before, and subsequently been sued, and lost, here in the United States as well as the EU.  Since it has been a few years since they lost their last lawsuit, it looks like they are at it again.