I edited the config.php file with new username and password.
After i change a translated word like "Twitter" wich became "Gorjeo" in Spanish, i have a pop-up asking for a password but nothing works.
It doesn't take it !
I used the defines user/password in that file and i also tried the administrator user/password of Joomla
Thanx to allhttp://www.atelierdusourire.com