Unable to install

[eluser]shoorace[/eluser]
I followed instruction given in http://ellislab.com/codeigniter/user-gui...index.html
I have set

Code:

//config.php
$config['base_url']    = "http://localhost/CodeIgniter_1.5.4/";

//database.php
$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root";
$db['default']['password'] = "";
$db['default']['database'] = "codeigniter";

But still there is problem, while running my http://localhost/CodeIgniter_1.5.4/

404 Page Not Found

The page you requested was not found.

So, is there still anything missing to configure?
Please let me know.

Thanks in advance.