How To Securely Erase Data From Hard Drive

Say you go to throw out a computer or sell it or give it to someone. There are steps you really need to take to make sure that your information on your hard drive is not recoverable. You have to securely erase data from your hard drive. And it’s not just a simple as deleting the files or even reformatting the hard drive.


You probably already know that if you go to delete a file in Windows it doesn’t actually delete it. It goes into the recycle bin and then if you delete that our the recycle bin, it still doesn’t go from the hard drive. That’s because what Windows does is simply marks that sector on the hard drive is empty, but it doesn’t delete the file itself.

So that will be still available to certain programs they can recover files until another program comes along, and rights over that blank space do erase whatever was on their previously. In the same as when you’re reformatting the drive. The drive simply marks all the sectors as blank, but the information does not go. so you could go back before anything else over rights it, and get that information back that’s not corrupted.

How can you securely erase data from hard drive

So then what can you do to make sure it’s completely gone? Well, it really depends on what you’re planning to do with computers. First let’s talk about if you just want to throw it out. Then in a case, the easiest and the best way to securely erase data is, just destroy the hard drive platters physically. So what I would do is just put a nail through with a hammer. This makes sure the platters can never spin again, and even if you took it into a clean room or something. That data is gonna be irreparably damaged.

Securely Erase Data

Now if you’re selling the computer I would say just remove the hard drive. But if you are giving away to a friend or something, and you need the hard drive to stay in there. There are some things you can do to securely erase data. First you can use a method that said to “Write Zeros”. This basically is just software that goes through the entire hard drive. It writes every single sector as zero. So even if you wanna go back in using software to recover deleted files, there’s nothing there, it’s written a zero blank.

So there’s no way to get anything back. It takes longer. But that method of formatting is probably the best. It’s pretty simple and you’re not gonna really get any information back from that.

However if you are really serious about securely erase data. Like if you think the government and the police are after you, there are some forensic techniques they could possibly use to get back the data if you only do one writing zero formats. And that’s simply because you theoretically could look at the actual magnetic fields and say, “all right this one looks like it used to be a zero”. And there are possibly some algorithms that could go through and maybe recover it.

So if that’s the case, where you absolutely need to make sure 100% that information is never recovered. There is software that will basically not just right over the blank space but also rewrites over it with random data. So the more it overwrites the less of the original magnetic fields gonna be distinguishable if at all even after one. So there are algorithms out there that will write using different methods. For example once called that “Gutmann method“. Which overrides up to 30 times and you can be sure that nothing has ever come back from that.

overwritting mathod Securely Erase Data

However, most of the methods usually just do at least 3 overwrites. And there’re some studies that show that even after one writing of zero with modern hard drives, you can’t be recovered at all. So it kind of is overkill. But if you really need that security and wanted to securely erase data from hard drive, then it’s probably a good way to go.


So that’s pretty much suggestive. I hope you guys enjoy this post. You ever gonna sell hard drive or want to securely erase data from it, now you know what to do. If you found this interesting definitely share it. If you want to leave a comment down below, I’ll be there as well.