Magento

Does anyone have any experience with WinXP, Magento & UniServer (http://www.uniformserver.com)?
I am trying to develop/customize a Magento store locally using UniServer to handle Apache/PHP/MySQL, however…

After various php.ini edits (to uncomment several extensions required by Magento - such as curl, pdo_mysql and mcrypt - and copy their dlls into the appropriate UniServer extensions folder), I still have the same problem starting UniServer and installing Magento.

On starting uniserver through the batch file, I get the message ‘procedure entry point php_pdo_declare_long_constant not found in library php_pdo.dll.  This message pops up twice, before okaying it the second time has uniserver start apparently normally.

Then, when at the localization screen of the magento install, I enter: English (Australian), E.Australia (time) and Australian Dollar (default currency), then when I click continue, I get the same error every time:

Fatal error: Uncaught exception ‘Exception’ in W:\www\app\code\core\Mage\Install\Model\Installer\Env.php:34 Stack trace: #0 W:\www\app\code\core\Mage\Install\Model\Installer.php(106): Mage_Install_Model_Installer_Env->install() #1 W:\www\app\code\core\Mage\Install\controllers\WizardController.php(271): Mage_Install_Model_Installer->checkServer() #2 W:\www\app\code\core\Mage\Core\Controller\Varien\Action.php(341): Mage_Install_WizardController->configAction() #3 W:\www\app\code\core\Mage\Core\Controller\Varien\Router\Standard.php(150): Mage_Core_Controller_Varien_Action->dispatch(’config’) #4 W:\www\app\code\core\Mage\Core\Controller\Varien\Front.php(147): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http)) #5 W:\www\app\Mage.php(424): Mage_Core_Controller_Varien_Front->dispatch() #6 W:\www\index.php(40): Mage::run(’default’) #7 {main} thrown in W:\www\app\code\core\Mage\Install\Model\Installer\Env.php on line 34

Can anyone offer any assistance?
Why the error?
What can I do?
Thanks in advance,