Go to C:\Program Files\EasyPHP\phpmyadmin\config.inc.php.
Look on line 85 ($cfg['Servers'][$i]['password'] = '<yourpassword>';) and enter your chosen password in there. Save the file then retry.
Look on line 85 ($cfg['Servers'][$i]['password'] = '<yourpassword>';) and enter your chosen password in there. Save the file then retry.