You need to restart the Apache server. In Windows, the IIS web server doesn't need to be restarted when you change the php.ini, but since you are using the Apache webserver, you need to restart it. Open the Apache Monitor, and click the restart button with the Apache2 service selected. (You can also restart it with the Windows Computer Management snap MMC.)
P.S. You know the PHP variables in your Apache configuration, since you can run the phpinfo() command...