I'm using Windows 8.1.
To open extensionless files, I have to double click/right click -> Open With on the file, then scroll down until I find whatever it is I think I need, usually notepad/notepad++, a hex editor, or an image editor/viewer. I tried to set a hex editor as the default program for extensionless programs, but I can't. I found an article from 1999 recommending the registry editor, and that would work, but this hex editor wasn't actually installed (it's just an .exe) and doesn't have anything in the registry. I don't have any reference for how to set it as a default program for the . extension in the registry.
After searching around a bit more, I found that, on win8, you can change file associations in Control Panel\Programs\Default Programs\Set Associations. And while I did see the . extension there, I can't seem to set a default program for it. The . extension is only there because I added in the registry, as ".".
Another method I tried is making an extensionless file, then going to its properties and setting the default program there. Unfortunately, the button to set the default program just isn't there.
Is there any way to accomplish this? And, for that matter, is there a reason I shouldn't be doing this? It seems awfully complicated, and I'm afraid it's for a good reason. The only article I can find that explains how to do this is from before Windows 2000 came out, which isn't a good sign.