When double-clicking a picture file, it shows
Then I choose "Select a program from a list of installed programs", and the "Windows Photo Viewer" is still there. I also check the "Always use the selected program to open this kind of file".
It can ultimately be opened. But when I open it the next time, the same thing happens again.
I go to "Control Panel\Programs\Default Programs\Set Associations", but could not find any extensions for the picture format, e.g. png, jpg, jpeg, etc!