Can't connect to a SQL Database using PHP

I am in the process of installing PHP and MySQL and believe I have done so correctly. I followed the directions in Kevin Yank’s book PHP & MYSQL
NOVICE TO NINJA
I have installed the Apache server, MySQL and PHP on my test machine. The server and the sql service all seem to be running fine.

Running a simple PHP program that attempts to connect to a SQL data base produces the following error message:

Fatal error: Call to undefined function mysqli_connect() in C:\Apache24\htdocs\mySQLTest.php on line 26

Obviously it can’t find the mysqli function. I double checked my installation especially the php.ini file and assured myself that I specified an extension=php_mysqli.dll

What could be causing the above error message. Is there another area of the installation that I should check / validate?

You might have more then one copy of php.ini lurking around.

Run this php code:

<?php phpinfo() ?>

That function tells you the configuration of your PHP server. Look for the value for:

Loaded Configuration File

That will tell you what php.ini file is being used by PHP and it’s the one that you should be changing (don’t forget to reboot the server if you’ve made changes to the php.ini file for the changes to take affect).

Does the

extension=php_mysqli.dll

have a ; at the start of it? If it does, remove the ; save the changed and then reboot the server