Why do some programs fail to be selected as the default program with which to open select file formats?

Question

I have files I'd like to open with SciTE or Sublime Text 3 (ST3) but when I right-click them and navigate to Open with→Choose default program... it opens up a new window (which I will call the Open with window). The problem I'm having is that that neither program appears in the recommended or other programs listed. Then when I choose the "Browse" option and click the exe file for either SciTE or Sublime Text 3 (which are in Program Files for ST3 and Program Files (x86) for SciTE) I'm left with the original Open with window with no sign of either program in the list of programs I can select to open the file with. When I open up browse for other programs and select them to open the file with a new program icon for the program appears in the list of programs I can open the file with.

Answer 1

Not sure why the application isn't added to the dialog. But you should be able to add the program using a tool called "OpenWithAdd"

Registering programs with the "Open With" dialog

Alternately, one could open the registry editor and manually register the application, using the info here:

Application Registration (Windows) The 2nd link is for advanced users, I'd say. Basically MSDN documentation is for use by developers.