Question PDOException (1045) how to enable?

[poolm]

SQLSTATE[HY000] [1045] Access denied for user ''@'localhost' (using password: NO)

i get this error while my partner said ask your provider to enable this module

i found it in php ini and uncommented it ... somehow it doesnt work
STILL


extension=php_openssl.dll
extension=php_pdo_firebird.dll
extension=php_pdo_mysql.dll
extension=php_pdo_oci.dll
extension=php_pdo_odbc.dll
extension=php_pdo_pgsql.dll
extension=php_pdo_sqlite.dll