SelectEx - Extended selection utility
SelectEx is Windows shell extension that expands Explorer's, Open and Save as dialog box's file selection capabilities. SelectEx is installed into Windows Explorer's popup menu, so you can access it by just one mouse click.

What is Windows Shell Extension
Windows Shell Extension is a program that adds menu items to context popup menu in Windows Explorer as well as in Open and Save As dialog boxes. Popup context menu is a popup menu that appears when you click on an object in Windows Explorer, or in Open and Save As dialog boxes, using right mouse button. Depending on the type of object you click on, a file or a folder, the menu is slightly different. In other words, in different "contexts" different "context menus" will appear. SelectEx adds up to four menu items to that menu.