phpBB : Critical Error

Could not connect to the database PHP Warning: mysql_connect() [function.mysql-connect]: Client does not support authentication protocol requested by server; consider upgrading MySQL client in F:\starthinker2\forum2\db\mysql4.php on line 48 PHP Warning: mysql_error(): supplied argument is not a valid MySQL-Link resource in F:\starthinker2\forum2\db\mysql4.php on line 330 PHP Warning: mysql_errno(): supplied argument is not a valid MySQL-Link resource in F:\starthinker2\forum2\db\mysql4.php on line 331