Thread:Project:Support desk/Can't upgrade (xampp)/reply

The error

DatabaseBase::factory no viable database extension found for type 'mysql'

means that MySQL is not available from inside PHP. You can upload a PHP file to your server with the following content:

<?php phpinfo;

When you call this file with your webbrowser, you will see information on your PHP installation.

Make sure that the MySQL extension of PHP is enabled (by editing php.ini)! After you enabled it, restart the server for your changes to take effect. The phpinfo output then should contain a section on MySQL and it should say that MySQL is "enabled".