Why do I sense that that will be a tough nut to crack?
Oh well, no matter. I'll just make that change manually, in the registry.
If anyone's interested, it's this key:
And change (default) to:
Sorry for the slight necro but I just installed Paint.NET on Windows 10 and it is not the default image editor. Is that a known bug that will be fixed in one of those important bug fixes you mentioned?