Horrible information you gave nikorr lol, i have been recovering hard drives for about 2 years now and i can say even if you cant see the drive in windows it can still be good. Such as the file partition table got corrupt or deleted. I have used utilites such as disk digger to recover files from drives that you cannot see in windows.
If you want to try and repair the drive i recommend using something called HDat2 or Diskgenious which are found on Hirens Boot CD and they repair bad sectors in the hard drive to make it work again. This is free to download from their website. Try these options before giving up hope and just junking what could be a good drive.
DiskGenious did the trick for me, just needed to reassign a letter to the drive. Cheers!