When you right click on a file in Explorer, the valid choices for that extension are presented. To add a new choice, select view/options/File Types. Scroll to the file type you wish to ammend, select it, and click the Edit button. Click the New button. Type the "Action" (Edit, Smile, Print, view, ...) and the full path to the application (and any command line switches/parametets) required to perform the "Action". If you want to change an "Action", click "Edit" instead of "New". I suggest you edit the "Actions" of "Text Document", "Write Document" and any type that uses DDE such as "Microsoft Word Document" to see the possibilities.