Ndi Extensioner is an easy-to-use tool that builds a list of all of the known file extensions on your PC, and their corresponding registry entries. You can then check all of the information relating to each type of file, including the context menu items that the file type adds to Windows Explorer, and the actions associated with the file type. The tool allows you to disable the items you don’t need, meaning you can get rid of context menu items that you never use, making Windows Explorer more efficient.