INDD files will only open with InDesign CC (original version) from file explorer (Windows). I can't change the default association! If I try to go to "Open with..." ID 2015 is not in the list, and it is not in the list for "Choose another app", and if I choose "...another app on this PC" it will still open in CC even after I've chosen ID 2015 in the Program Files folder! Help...!
Windows uses the most recently installed version by default.
The most recently installed was InDesign 2015. Surprisingly.