Case Study: Error Moving File

Let's look at a classic message box that is completely unnecessary. Have you ever selected a folder in Windows Explorer and received the following error message?

Over the years, I have received this error message hundreds of times. You get it when you select a folder in the All Folders pane of Windows Explorer and move the mouse slightly before you release the button, which is interpreted as an attempt to drag the object onto itself instead of as a selection. However, not once did I actually intend to perform this action. Doing so wouldn't make any sense.

Why is this error so bad? The text is certainly easy to understand. The problem is that the message is completely unnecessary—there shouldn't be a message at all. Rather, Windows Explorer should simply treat a folder being dragged onto itself as an accident and should only select the folder. Feedback isn't necessary, since if I really did intend to copy a folder to itself, no action would be required.