Okay, but then we're back to the same problem. There is no mention of the auto installer in the instructions, and when you get to step 11 (configuring FEC) you're stuck because there is no FEC menu item in the admin configuration panel. How do I run the auto installer?

If you take feature requests, disabling guest checkout when downloadable products are in the cart would seem like an important addition. Perhaps just as a configuration option in case future versions of Zen Cart will allow emailing of download links.