Install Instructions:
#5
5. Edit dbprefs.php (/src/admin/dbprefs.php) with your database information and aiml directory information. Fill out values for $DB_HOST, $DB_UNAME, $DB_PWORD and $DB_DB. Use the Absolute Path to the AIML directory for $rootdir. If it turns out wrong in step 7, come back here with the path botloader.php includes in its error message.
For Windows set the rootdir in dbprefs like:
Line 92 of dbprefs:
c:/htdocs/alfredo/aiml

#8
8. Access talk.html (http://www.yoursite.com/alfredo/src/talk.html) from your web browser and say something to the TestBot.

It's  http://127.0.0.1/alfredo/src/talk.php
or
http://localhost.com/alfredo/src/talk.php

Sometimes Localhost is not set but 127.0.0.1 is the Ip and always
works.

Please fix the Install Instructions on the web and in Distribution.