We've frequently observed that application extensions path is setup incorrect in IIS property of your domain. The correct application extension path should be set as "C:\Program Files (x86)\PHP\v5.6\php-cgi.exe" in IIS. Please follow the given procedure to set correct PHP extensions path:
IIS6
- Go to "IIS".
- From the website property select "Home Directory"
- From the "Configuration" in the "Application Extensions" .php extention, set the path to "C:\Program Files (x86)\PHP\v5.6\php-cgi.exe".
IIS7/8
- Go to "IIS".
- Click on servername. Now, search for PHP Manager and double click on it.
- Under PHP setup, "PHP executable" should have path as: "C:\Program Files (x86)\PHP\v5.6\php-cgi.exe"
- If it does not show the path, you can click on "Register new PHP version" and add path for php-cgi.exe
NOTE: We consider that you have PHP version 5.6 is installed at C:\Program Files (x86)\PHP\v5.6\ location. You will have to change it based on your installation path.