How can I disable copying files via drag-and-drop in Windows Explorer in Windows 7?
Note that I don't want to disable drag-and-drop completely nor in the start menu, just disable copying (duplicating) files when users drag-and-drop.
Windows doesn't provide a built-in way to change the default action of drag and drop, but I found a tool called Drag'n'Drop Editor which will let you change the default action to "move".
This doesn't disable copying (you can still hold Ctrl to make a copy), but it should help prevent accidental copies.
Perform the following steps :
This should do the trick.