Hi nabil_kadimi,
I followed your steps (with a fresh install, as I hadn't built anything on this install yet), but now a new issue has arisen.
I installed wp, created a database & user, then opened wp-activate.php in firefox and was greeted with a 500 error right off the bat.
Also no, there is no .htaccess file in the wp root folder.
@8183: No, I do not use front page, thankyou.