Here are few steps that must be followed carefully
Create a folder named config inside C:\wamp\apps\phpmyadmin, the folder inside apps may have different name like phpmyadmin3.2.0.1
Return to your browser in phpmyadmin setup tab, and click New server.
Change the authentication type to ‘cookie’ and leave the username and password field empty but if you change the authentication type to ‘config’ enter the password for username root.