Boot into BIOS setup to see if you can find any listing showing the HD is still alive. If so then run the maker's HD Diagnostic extended CD scan, following by a Disk Check from the installation DVD or Repair CD's Command Line.
If no sign of HD listed anywhere in BIOS - usually by a serial number you can google to find its make/model - then try reseating it or changing its cable to get it to register.
i tried everything,also opened hdd to see it there was everything all right,but when i pluged it it started working and in few second it stopped.
i think that it's dead and i'm going to change logic board