Normally, users and applications can copy, move, delete, or rename folders with few restrictions. A program that implements a copy hook handler can control whether these operations take place. For instance, a copy hook handler can prevent critical folders from being renamed or deleted. Copy hook handlers can also be implemented for printer. The Windows Explorer Shell calls all registered copy hook handlers every time an application or user attempts to copy, move, delete, or rename a folder or printer. The handler does not perform the operation itself, it only approves or vetoes it. If all copy hook handlers approve, Windows will perform the operation. However, if any copy hook handler vetoes the operation, it is canceled and the remaining copy hook handlers are not called.