Customizing Windows Right-Click menus with multiple levels

Answer 1

You need to write a Shell Extension; there is a guide for writing one in managed code (C#) here. It will involve doing a bunch of interop and implementing COM interfaces that the windows shell will consume, namely IShellExtInit and IContextMenu.

However, one could argue that writing a Shell Extension in managed code is not advisable; it will force windows explorer to load the CLR, (or any app that uses the standard windows 'Open File' dialog) - native code (C++) would be a better choice for this.