are you sure, that your eZ installation is running correctly? This error comes along when you have the settings DatabaseImplementation not set correctly or the file /lib/ezdb/classes/ezmysql.php could not be read. You should investigate it.
First try to call the home page of your installation.
Then check if the settings are set correctly (You have windows. so check all whitespaces, they might cause problames)
Check the permissions of the lib directory and its content.