Every three or four years I need to install PHP on a new Windows laptop. And each time I go through a battle - it's so confusing to find simple instructions on how to do it. Here are the steps I used in February 2018. It should take 5 minutes if all goes well. Fingers crossed...
Firstly you need to make sure you have IIS running. Here's my article on installing IIS
Download the correct version of PHP for your machine's hardware from the Windows PHP documentation. Note that it says:
If you are using PHP as FastCGI with IIS you should use the Non-Thread Safe (NTS) versions of PHP.
That means you should be downloading this file
However this file came down at an agonisingly slow speed so instead, I downloaded PHP from http://php.net/manual/en/install.windows.manual.php
Unzip this file. I unzipped it at c:\Program Files (x86)\php. Take a copy of the file php.ini-production and rename it to php.ini
Open IIS and at the root node click on Handler Mappings
Then select Add Module Mapping
Note the details of the module
This has wired PHP into IIS. To test it, create a PHP file and execute it as per the test script I set up on the IIS install page.
<?php phpinfo(); ?>
If the installation has been successful the php details should show if all is OK
That's it - I hope this works for you!