Context Menu Extension The DROPEXT sample demonstrates how to extend the drag-and-drop context menu. To test DROPEXT.DLL, you must: 1. Build DROPEXT.DLL. 2. Copy DROPEXT.DLL to the system directory (for example, c:\windows\system). -or- Modify DROPEXT.REG file to points to a fully qualified path to the DLL. 3. Run the command: regedit dropext.reg. 4. Use the right mouse button to drag a file from one folder to another. You will see additional menu items for the drop operation.