Ultra stopped using Windows Media Player

I am a Luddite.

I have renamed a number of video files before loading them onto a Cruzer Ultra over the last couple years. When double-clicked, some would open in “Media and TV”, some in “Windows Media Player”.

After my latest Windows update, Ultra does not find WMP.

When I doubleclick on the videos WMP would previously have opened, I get a message that reads: “The application can not open it because it can not find any editors for this type of file”.

Files opening in “Media and TV” are unaffected.

What can I do?