How to enable Drag and Drop for a file?

Question

Windows

What should be added to the registry to enable the ability for a file of its extension to be drag and drop? How is it done for folders, exe, bat, shortcuts and some other extensions?

Answer 1

What should be added to the registry

Nothing.
If the program handles the "Drag and Drop" mechanism correctly, it will work, otherwise it won't.
And what extensions and how it will process depends solely on the programmer.