One click Installers from hosts, usually have a different set of files, then the default phpBB Installation, which can be found here at phpBB.com
Usually, what I do, is once my website is visible on the Internet, is download the latest version of phpBB from phpBB.com, and upload all the files into my
folder, and then browse to http://yourdomain.com/install/index.php
which will allow you to proceed with the installation.
In my opinion, this is the only way, I currently know of, to be sure, you have all the files, from the "vanilla" installation of phpBB, and not the files used by a Host's One Click Installer.
Just a suggestion folks