Description:
------------
---
From manual page: http://www.php.net/class.pdo
---
When installing PHP5.3, there is no php_pdo.dll included with the PHP package. 
It's therefore impossible to use any of the PDO database drivers. 

Plus, using the php_pdo.dll from the latest PHP5.2 archive doesn't work because 
new constants aren't available to it.

Test script:
---------------
<?php
$pdo = new PDO( 
    'mysql:host=hostname;dbname=defaultDbName', 
    'username', 
    'password', 
    array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8") 
); 

Expected result:
----------------
$pdo should be a connection to a database

Actual result:
--------------
Fatal error: Class 'PDO' not found ...