Following steps needed only if you want to use php script on httpd (probably won't need that for a while)...
Replace your ioFTPD\text\http folder by the 5.7.x package ioFTPD\text\http2
You have to
download Windows binaries of PHP and install it on same box where your FTP is. All you have to do is:
1) extract archive to C:\php
2) rename php.ini-dist to php.ini
3) place it in your Windows folder
Following steps needed only if you wanna make php scripts for httpd.
4) open that php.ini file that you've just copied to your windows folder
5) search for
extension_dir and change it's value/setting to
c:\php\extensions
6) save file (dooh)