The system requirements of Magento are quite extensive, it requires at least PHP 5.2.0 extended with mcrypt, PDO_MySql and simplexml. For the database Magento needs at least MySQL 4.1.20 with InnoDB storage engine. At MagentoCommerce.com you can find a complete list of requirements. But how do you know if your server meets these system requirements? …Read: "Magento performance hosting"