After making these changes, I ran the site and a login box was popping up, and when I cancelled it, I got a 401.2 error. For some reason, Windows Authentication had been switched on. This was coming from a configuration file managed by IIS Express.
To find IIS Express configuration for your currently running sites quickly and easily:
Find the tray icon for IIS express
Click on it and this menu will appear:
Click Show All Applications, and a list of running applications will be displayed:
Click on an individual site name and you will see more details including the path to the applicationhost.config for this site: