thank you for your answer
please look in what i have
in CMD i type "list partition" for "disk 0" (the only one i have ) and i have that :
partition 1 principale
partition 2 etendu
partition 3 logique
partition 4 pricipale ( the one i ve prepared to install osx in )
but the problem is : disk utility does not recognize the hole disk 0 : the only one in list is the usb drive !!!!!!!!!!!!
please help me out