Access denied for user 'root'@'localhost' (using password: YES)

The most possible cause of this error is an incorrect password. To confirm this, please execute the below command from your shell.

mysql -u root -pxxxx

xxxx is your root password. The server should let you connect without any error in this case.

To find out other possible causes, please follow the below article.
http://dev.mysql.com/doc/refman/5.1/en/access-denied.html