Bueno pues parece que el problema es cuestion de permisos, estas seguro que tienes creado ese usuario, con ese password, porque segun la documentacion de XAMPP solo tienes el usuario root por defecto y sin password:
Cita: //Extractado de la Documentacion de XAMPP
* MySQL and PHP
MySQL starts without a password for "root". So in PHP you can connect the MySQL-Server with:
mysql_connect("localhost","root","");
If you want to set a password for "root" in MySQL, please use "mysqladmin" under Console. For example:
\...\xampp\mysql\bin\mysqladmin -u root password secret
Attention. After changing the password for root, don't forget to inform PHPMyAdmin. Search the "config.inc.php" under \...\xampp\phpmyadmin\ and edit the following lines:
$cfg['Servers'][$i]['user'] = 'root'; // MySQL SuperUser
$cfg['Servers'][$i]['auth_type'] = 'http'; // HTTP MySQL authentification
Now the correct password for "root" is required, before PHPMyAdmin starts.
Please see also the three methods in the Windows FAQ:
http://www.apachefriends.org/en/faq-...html#password0 tal ves esto te ayude, saludos, cya