Indicates that Drupal has already been installed.
function install_already_done_error() {
global $base_url;
drupal_set_title(st('Drupal already installed'));
return st('<ul><li>To start over, you must empty your existing database.</li><li>To install to a different database, edit the appropriate <em>settings.php</em> file in the <em>sites</em> folder.</li><li>To upgrade an existing installation, proceed to the <a href="@base-url/core/update.php">update script</a>.</li><li>View your <a href="@base-url">existing site</a>.</li></ul>', array(
'@base-url' => $base_url,
));
}