How to solve PHP Extensions “0” must be loaded?

Question

I am trying to install Magento on my server. I did everything, as written in docs. I have following error:

PHP Extensions “0” must be loaded

Answer 1

You have to install the PHP 5.4 support package:

"PHP 5.4 support - Enables Magento to work with PHP 5.4 - Added Jan 17, 2014" http://www.magentocommerce.com/download

Answer 2

If you are installing Magento version 1.7.0.1, try the following to solve your issue:

Replace in file app/code/core/Mage/Install/etc/config.xml (near 71th string):

<extensions>
    <pdo_mysql/>
</extensions>

with this

<extensions>
    <pdo_mysql>1</pdo_mysql>
</extensions>