Recreate file associations?

[random832 at fastmail.us]

On Mon, Jun 29, 2015, at 14:25, Terry Reedy wrote:
> Registry => Windows.
> Did you check [X] Make this my default python?

I didn't see any such checkbox, in any of installers I ran.

(And, yes, I assumed windows was implied by my subject - other systems
python runs on either don't have a notion of "file associations" or
don't use them as the mechanism for executing python scripts)