This applies to xampp-1.5.3a:
(don’t know about other versions since I only have this one. It works also for xampplite)

Yes, after a fresh install of a xampp program you are welcomed with a xampp pseudo website which is located in <path of xampp installation>/htdocs/xampp/. Clicking security you are given some important points to secure your website. That includes changing the root password. But alas, after changing it you’ll not be given a chance to use the ever-friendly phpMyAdmin.

Find <path of xampp installation>/htdocs/xampp/phpmyadmin/config.inc.php

$cfg['Servers'][$i]['password'] = ”; // MySQL password

Change this so that it’ll reflect your current mysql password.

$cfg['Servers'][$i]['password'] = ‘your_password_here‘; // MySQL password

Don’t forget to save it aight?!