server transfer problems
 

I have recently moved my forum from one server to another and have reloaded all files and databases but now get the following;

Database error in vBulletin :

mysql_connect() [function.mysql-connect]:
Access denied for user 'root'@'localhost' (using password: YES)
/home/site/public_html/forums/includes/class_core.php on line 271

any ideas on how to get this fixed as have tried most things and running out of ideas.