The PDO extension is required for this adapter but the extension is not loaded

#0 /home/desireto/public_html/1plus2_pub_html/lib/Zend/Db/Adapter/Abstract.php(248): Zend_Db_Adapter_Pdo_Abstract->setFetchMode(2)
#1 /home/desireto/public_html/1plus2_pub_html/app/code/core/Mage/Core/Model/Resource.php(175): Zend_Db_Adapter_Abstract->__construct(Array)
#2 /home/desireto/public_html/1plus2_pub_html/app/code/core/Mage/Core/Model/Resource.php(110): Mage_Core_Model_Resource->_newConnection('pdo_mysql', Object(Mage_Core_Model_Config_Element))
#3 /home/desireto/public_html/1plus2_pub_html/app/code/core/Mage/Core/Model/Resource/Setup.php(141): Mage_Core_Model_Resource->getConnection('core_setup')
#4 /home/desireto/public_html/1plus2_pub_html/app/code/core/Mage/Core/Model/Resource/Setup.php(234): Mage_Core_Model_Resource_Setup->__construct('core_setup')
#5 /home/desireto/public_html/1plus2_pub_html/app/code/core/Mage/Core/Model/App.php(417): Mage_Core_Model_Resource_Setup::applyAllUpdates()
#6 /home/desireto/public_html/1plus2_pub_html/app/code/core/Mage/Core/Model/App.php(343): Mage_Core_Model_App->_initModules()
#7 /home/desireto/public_html/1plus2_pub_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#8 /home/desireto/public_html/1plus2_pub_html/index.php(87): Mage::run('', 'store')
#9 {main}