PHPStorm reports "Debugger: Not Installed"

In [settings/Languages&Frameworks/PHP] in CLI Interpreter it says "Debugger: Not Installed"
The PHP Executable is pointing to the correct PHP exe 5.6.31

The following entries have been added to the Apache php.ini [xdebug] section (and xdebug dll placed in correct folder)
zend_extension = c:/wamp64/bin/php/php5.6.31/ext/php_xdebug-2.5.4-5.6-vc11-x86_64.dll
xdebug.remote_enable=on
xdebug.remote_host=localhost
xdebug.remote_port=9000

After spending far too long trying different configuration ended up nothing worked to get PHPStorm to say "Debugger install ok"

(Note: am not configuring Xdebug for using in the On-Demand mode)

As a last resort tried to see if debugger actually worked, so set breakpoint in php file, enabled Chrome debug cookie, enabled PHPStorm start listening for PHP debug connection, and ran php file, and found debugger is working, which really surprised me!

*** 1st question how do i get PHPStorm to report that Debugger is in fact installed?

2nd I tried actual debugging with the following php.ini files, restarted web server, and this did not work??
zend_extension = c:/wamp64/bin/php/php5.6.31/ext/php_xdebug-2.5.4-5.6-vc11-x86_64.dll
xdebug.remote_enable=on
xdebug.remote_connect_back=on

*** 2nd question from tutorials I watched online I understood that [xdebug.remote_connect_back] meant that no host nor port had to be specified in php.ini

I am very new to PHP and PHPStorm so have a very steep learning curve. I would appreciate some feedback as where I am going wrong in my setup of PHPStorm

One other thing I am really confused about is the web servers, I understand PHPStorm has it's own web server, and uses an existing PHP installation for it (probably among other things too), hence pointing the CLI Interpreter PHP executable to the php.exe. So then I thought it was that php.ini that needed mofifying, but that made no difference. I have WAMP installed and am running on Windows 10

** 3rd question could someone explain to me how the PHP internal web server works as to what is the architecture?

I really appreciate your assistance

Thank you, marc