Destroying your Hard Drive on Purpose
Smash it with a hammer and use a hacksaw. You probably think I’m kidding don’t you? Well, I’m not. There’s no way a hard drive that is in tiny pieces will ever be salvaged—to use for data recovery, anyway—so you will certainly be safe. Take out your aggressions, but be sure that you are wearing the appropriate safety equipment as pieces will go flying!
Use a really big magnet to demagnetize your hard drive. Gather some magnets (it may take a bit to get enough of them to make one powerful enough to destroy it) and pass the drive over the magnets repeatedly. Move the magnets around to be sure you get enough exposure. The hard drive will be intact, minus the data or the ability to recover the data.
Grind it to dust. Using a vice, clamp the drive to a place where you know it is sturdy and will not move. Take a grinder and have fun turning your hard drive into a pile of dust. You’ll never have to worry about any data being recovered then!
Burn it with acid. Make sure that you have all the required safety equipment including safety glasses, and gloves that are acid resistant. I also suggest that you wear a suit over your clothing. In a large container, pour enough acid into the container so that when you lower the drive into it, it does not splash over the sides. Attach a wire to the drive so that you can lower the drive into the acid without touching it. Leave it sitting long enough to work its way in, and if you want to really watch it go, expose the acid to sunlight. Remember though, this will cause the acid to bubble up so you need to make sure that you are really well prepared for the reaction.
Burn it with Thermite. This is a chemical used by the military that burns at around 3000 degrees Fahrenheit, so it may not be easy to get your hands on. If you do manage it, place the hard drive in sand away from other flammable materials, put a few pounds of Thermite on top, ignite it, and watch it burn. After it has burned long enough to amuse you and assimilate your drive, make sure the fire is completely out. Be sure to practice the appropriate safety behaviors so that you do not burn yourself.