Prevents generation of 'Hello World' and 'Sample Page' in WordPress, just drop this file in your wp-content folder before running the installation.

install.php

<?php

/**
 * Prevents generation of 'Hello World' and 'Sample Page'.
 * @link http://wordpress.stackexchange.com/a/71867/8872
 */
function wp_install_defaults() {
    return null;
}