On W32, the shell can do the right thing with every file, because extensions are registered with the explorer. See MsShellExecute.
When a file is ‘right-clicked’ from explorer, some of the available actions are ‘verbs’. The default verb is displayed in Bold face (in the right-click menu), and will be executed by default (from a double-click). WThirtyTwoShellExecute exposes all of these verbs to the emacs user whether visiting the file, or while in Dired.
If you use Dired+ with w32-browser.el you can take advantage of MS Windows file associations in Dired. Just use
‘C-RET’ to “open” a file using its file-association Open operation. Use
‘M-RET’ to open Windows Explorer to that file or folder.