Where are a user's input settings stored? How can they reset them?

Got this tweet from a player today:

any way to reset the controls to
default? i was toying with it and
changed left mouse click … can’t
change it back

And I can’t find anything. PlayerPrefs are stored in the registry but when I looked there all I saw were the PlayerPrefs, there was nothing about customized user input. I tried overriding the defaults myself and looked for changed files in AppData or in the application directories themselves and also nothing.

The stuff has to be stored somewhere. Where?

Also - the tweeter is on Mac Os X. I gather it’s in the registry if it’s Windows - where is it on the Mac?

It would be nice if there was a “Reset Defaults” button on the Input tab of the opening dialog box, but since there isn’t…

On Windows it’s indeed in the registry - search for the name of the game and delete the key

Isn’t Windows registry editing a bit too easy just to reset input options? I would make it much more complicated…
Seriously: add a Reset settings button.