By mistake i have deleted user 'root'@'localhost' in phpMyAdmin, and now it doesn't opens.
It shows the following error:
Welcome to phpMyAdmin
#1045 - Access denied for user 'root'@'localhost' (using password: NO)
phpMyAdmin tried to connect to the MySQL server, and the server rejected the connection. You should check the host, username and password in your configuration and make sure that they correspond to the information given by the administrator of the MySQL server.
Even uninstalling and reinstalling the wamp server doesn't help.