in WAMP, phpmyadmin password is stored in config.inc.php

wamp directory\apps\phpmyadmin\ config.inc.php
in my case
c:\wamp\apps\phpmyadmin3.3.9\ config.inc.php
open this file in notepad

When this information required?
While installing WAMP we usually install mysql in without password mode.
After working we may set password to the mysql database.
After the password change the phpmyadmin will not work.
Do necessory changes in the phpmyadmin configuration file "config.inc.php"
Restart the WAMP server.
Start phpmyadmin. It will work without error.