1st thing I'd do is go to the program properties to make certain that the compatibility setting is correct. I'm thinking Windows 95 or 98 would work best. If you still can't drag and drop, you should still be able to have the program open any given associated file.I was able to do this for ages, then recently I can no longer do it.
I am using windows 10 CEP 2.1, I ran as an admin and still can't do it.
Not sure what changed that makes it so I can't drag files into it, is it a windows 10 thing they recently added?
Any ideas would be help.