Windows 10 -- Making the Simple Impossible

On several occasions, I've tried to use Windows "Photos" app to view image files. On many occasions, it just displays blackness, so I have to use Windows Photo Viewer (the more traditional solution). My little sleigh ride through hell today:

• Try to open an image (JPEG) but "Photos"  app displays black
• Open same file from Explorer using "Open with". Photo Viewer works like a charm
• Want to change Viewer to be the default, but can't directly from Windows Explorer (I think, the right-click menu has about 20 options, so who knows)
• Google changing file associations in Windows 10 and it tells me to select "Default programs" from start menu
• Start menu doesn't work. For some reason it randomly flakes out on me. Start menu won't come up and right-click menu on apps in the task bar won't work (this has been happening for weeks)
• I find my way to default programs anyway, but when I choose a default program for Images, the UI doesn't change to reflect my selection (although the association for images seems to have been modified)
• Same thing for video (I want to use Media Player instead of the dreadful Windows 10 default). Also doesn't update the UI for default video program to show the new selection and the association hasn't been changed.

It's 2016 people.

BTW, just found how to change file associations from Explorer:

• Right-click
• Choose Properties
• Click Change button in section on "Type of file"

This wasn't listed in the articles that came back in my Google search.