if you cannot remember your phpmyAdmin login details, go to your xampp installation location and look for the following file:
\xampp\phpMyAdmin\config.inc.php
in this file look for the following lines:
/* User for advanced features */
$cfg['Servers'][$i]['controluser']
$cfg['Servers'][$i]['controlpass']
the controluser is the user name. the controlpass is the password.