unable to log in_local machine

Hi,
pretty new to all this.
I wanted to familarise myself with wordpress on a local machine as i knew im very ignorant of a lot of concepts, terms etc

Have followed the steps outlined here
http://www.tamba2.org.uk/wordpress/xampp/
that helped me load wordpress and xampp onto my local machine.
All went well. I was looking at alternative themes when i had a crash. They on reboot, cant seem to figure out how to log in again.

Im pasting in this url into explorer to bring up my wordpress
http://localhost/wordpress/wp-admin/install.php
(which worked before when i loaded wordpress)
but now does not. IS this my issue, OR

Ive since changed my password to “JoePass”
my user is still “admin”

my wp-config looks like this (as instructed from tamba2.org instructions listed above )

define(‘DB_NAME’, ‘wordpress’); // The name of the database
define(‘DB_USER’, ‘root’); // Your MySQL username
define(‘DB_PASSWORD’, ”); // …and password
define(‘DB_HOST’, ‘localhost’); // 99% chance you won’t need to change this value

do i need to alter it to reflect the above changes i made to password?

any direction would be great