oh thank u soo much man for replying.
hey i tried that but it didnt work, i played with the offsite thingy but nothing. it is +900rpm or nothing (btw they are not pwm, but still i can get 500rpms in the bios !!) technology is weird man.
also, there is no software to control the fans in my os !! i have a gigabyte mb, so u know the reason.