when i get to the final base, right before Clicking the Install , i don't get the PostgreSQL installation zone crossed , i only get Server installer crossed

like this :    (check) Server OpenERP

                  (         )  Installation du serveur de base de donn?e  PosgreSQL utilis?e par OpenERP

I already tried uninstalling everything ( with IObit unistaller) and RE-installed it Again and again, but the same problem still remains!!