Treat the platters like a murder weapon. After you destroy them, throw them away in different trash receptacles. Make sure that they’ll never be reassembled. However, if you properly scratch, bend, demagnetize, and break the platters, it won’t matter if a forensics team gets a hold of them; the data will physically be removed from the disk. At this point, data recovery is impossible because, well, there’s no data to recover.

Using Software

Don’t want to destroy the hard drive? Still want a secure way to get rid of the data? Well, it’s not that complex. Computer coding is written in binary code, which is represented by 1’s and 0’s. The Department of Defense has developed a standard method for writing over computer code in a way that quite frankly, isn’t as fun as throwing shiny metal discs at my neighbor’s pets, but is much more cost efficient for people that want to resell or give away their computers.

The Department of Defense’s method is known as DoD7. It recommends assigning a random date to the file, then writing over the original computer code with 0’s, or 1’s, or random 1’s and 0’s, then basically doing it all over again seven times. Hence the 7 in DoD7. Most of the time, by the second time the code’s rewritten there’s no chance of recovery, so seven rewrites should be overkill; still, it’s the good kind of overkill, so don’t assume you can run less rewrites to save time and still completely destroy your files.

You’re probably saying, “Wait, do I have to type over a program by hand in binary code seven times?” Well, no, that would be far too time consuming. Modern computer code is…well, let’s say very long, and doing this by hand isn’t feasible. Luckily, there are programs out there made for this exact purpose.

Try Eraser. Eraser is free software that does a secure deletion for you; to be safe, go ahead and run it a few times. If you want to completely erase your hard drive, programs can be found to do that by typing in “free secure file deletion” at Google.