Some hard drives need a "TORX" driver. Their the ones with the 6 points. I've opened many a dead drive. My work requires that when we scrap a hard drive, working or not, we have to "DESTROY" it. I've taken great pleasure in cutting the disc substrates up with a sheet metal cutter and burning the media and sanding the surfaces and plain ol just beating the crap out of them with a ball peen hammer. They won't let me use C-4 or a 44 mag.