Does Anyone know how to add context menu in win explorer on files? And how do they work? Do they call a command and put the full filename after the command as arguments?

can you be more specific with your win explorer?

;)

If you google, you'll find some examples based on registry editing. But I think that is not formally supported by MS, it's more like a hack. The formal way is to write Shell extension (MS dev docs refer to Win Explorer as Shell). You need to implement several COM interfaces (IContextMenu, IShellExtblahblah, etc). See how Tortoise or Notepad++ does it. Then you'll need to apply that knowledge to PyWin32 Extensions. Good luck.