File association for jpg files is not working with Photoshop CS5 on Windows 10

For some unknown reason after many years my .jpg files started switching from opening with Photoshop CS5 to Windows Photo Viewer. I was able to change the association back to Photoshop CS5 and it would be fine for a few days. Then it would change back to Windows Photo Viewer. This went on for a few months and now I can not get it to reset to Photoshop CS5 no matter how I try. (this is also true for my .png files)

I have tried to use the right click "Open with", "Choose another app", "Always use this app to open .jpg files".

I have gone into "Settings" and tried all variations to associate .jpg files to Photoshop CS5 with no luck.

I have tried the right click "Properties", "General", "Opens with" and "Change" and selected Photoshop CS5 with no success.

In all cases the Photoshop CS5 Icon is offered as an application choice, but the association never changes.

My .tif file association to Photoshop CS5 still works fine.

Any solutions would be greatly appreciated.