How could I add an entry to the right click menu ?

I'm not really sure how to google this one . I would like to know how would I add an entry to the right click menu in a Windows system . Something like "Open with ..." or "Archive with ... " . I would preffer a solution that works under Windows XP .

From stackoverflow

• in the registry, HKEY CLASSES ROOT houses the stuff you need.

  specifically

  (any file)
  HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers 
  
  (any folder)
  HKEY_CLASSES_ROOT\Directory\shell
  HKEY_CLASSES_ROOT\Directory\shellex\ContextMenuHandlers
  

  The old nvidia rightclick on desktop feature would remove the "new" from folders when you uninstalled the driver. So I had to figure out how to restore it.

  Good luck.