How to wipe a hard drive so your data is truly erased
You’ve just purchased a shiny new laptop, and now you’d like to donate your old computer, give it to a family member, or recycle the hardware. We applaud your sustainable choices! But wait – have you deleted all the data on your hard drive? Is it really, truly gone? Or can whoever gets your old device recover any of it?
by Alyssa SchmittBefore you start enjoying your new laptop, do a hard wipe of your old one
Even if you conscientiously deleted all your files, operating systems don’t completely wipe away the data; instead, files are kept on the disk until they are overwritten with new data, even if you can’t see them. This means deleted data can still be restored – a feature we appreciate in other circumstances, like when we accidently erase that report that’s due tomorrow. And this can even apply if you’ve emptied your computer’s recycle bin, because there are a variety of utilities out there for recovering deleted data.
How to securely erase a hard drive
The fact is that the drive has to be completely overwritten before your old data is securely destroyed, a process known as a disk wipe,a hard wipe, or secure erase. The most cited security standard is that the data should be overwritten at least three times in order to truly erase a disk.
Good to know: What is “secure erase”?
On an SSD hard drive, the “secure erase” command is intended to completely overwrite all data contained on the drive. It is part of the built-in firmware of modern SSDs. Secure erase works by overwriting the data with binary ones or zeros. Once the secure erase process is complete, it is impossible to recover any data from the hard drive.
How to securely wipe a hard drive on a computer that works
For a laptop that can be booted up and still works, wiping the drive is a straightforward procedure. You’ll find a utility for securely erasing the computer’s drive(s) right in the settings. Whether your computer is going to the recycling center or to another person, you can wipe the entire drive by following the steps for your specific computer below.
Before you wipe your hard drive:
Keep in mind that this is the nuclear option: Once you have wiped a disk, your data is gone for good. So, check – and double-check – that you have stored any files you still need on a separate device before you proceed.
In addition, if you are wiping the hard drive on a laptop computer, plug it in before you start so the battery does not die in the middle of the disk wipe.
Finally, you should be aware that securely wiping your entire computer will take several hours – it’s not something you can do as you rush out the door on your way to drop off your computer for donation.
How to format your hard drive so that it cannot be recovered
Securely erase your hard drive in Windows 10
Go to your Settings > Update & Security > Recovery
Under Reset this PC, select Get started
Click Remove everything
To ensure that all data is removed, you’ll need to go to Change settings in the Additional settings screen. Here you should activate Clean data and Delete files from all drives.
Click Confirm
Securely erase your hard drive in Windows 11
Open your settings and go to Update
Select Recovery in the side menu
Choose Reset PC
Click Remove everything
Click Change settings and make sure that Clean data is activated
Click Confirm
Wipe hard drive on a Mac
A Mac that uses macOS Monterey or later has an option called Erase all Content and Settings. It features an erase assistant with step-by-step instructions you can follow to restore your Mac to its factory settings.
Erase your Mac with Erase all Content and Settings:
Go to the Apple menu and select System Settings
In the sidebar, click General
Click Transfer or Reset
Select Erase All Content and Settings
Follow the onscreen instructions
If you do not see the “Erase all Content and Settings” options, never fear! You can go to Disk Utility to wipe drives.
Erase drive(s) on your Mac with Disk Utility:
Restart your Mac
Hold down Command + R to start recovery mode
Click Disk Utility
In the sidebar, select the drive you want to wipe
Click Erase and select a file system format
Under Security Options, choose how many times the erased date should be overwritten
Click Erase > Done
Programs you can use to clean a hard drive
For versions of Windows older than 8.1., you need a third-party program to wipe your hard drive, and you may want to look into this option even if you have the latest operating system. Why? A hard drive eraser utility gives you more control about the way your hard drive gets wiped – and maybe even more peace of mind when it comes to particularly sensitive data.
In many cases you can also use these tools to wipe individual files from a drive, or to wipe other devices such as USB drives.
When choosing a file erasing tool, you should check to make sure it will work with your operating system (Windows, MacOS or Linux) and drive type (SSD or HDD).
How do I wipe drives if I can’t boot up my computer?
If the computer in question no longer works, wiping the drives is a different story. You may be taking it to be recycled rather than reselling it, but just because you can’t boot it up doesn’t mean that your old data is not still there on the hard drive. So, this is where you should focus: Removing the hard drive.
Good news – it’s not usually that hard to remove a hard drive from a computer! Since each computer is different, we can’t give you exact instructions here, but in most instances it’s just a matter of opening the casing, locating the drive(s) and disconnecting it. You should be able to find a YouTube tutorial for your specific model. Alternatively, you could just take your computer to an electronics or computer repair shop, where it should only take a few minutes to remove the hard drive (and while you are there you can find out if the store also offers a drive shredding service).
Physically destroying a hard drive
What to do with the hard drive once you get it out? Physically destroying the hard drive ensures that your data can no longer be recovered.
Why not try a DIY approach? Since your goal is to destroy it, there is not really a lot that can go wrong as long as you take the necessary safety precautions. In other words, your first step is to put on some safety glasses and protective gloves and find a safe area to work (away from pets and small children, please!)
Now you can smash the drive with a hammer or a large rock, drive nails through it, drill holes in it … anything you fantasized about when your computer ticked you off in the past. Any method will do, as long as you destroy the hard drive platters in the case of a HDD, or the flash storage chips if you have an SSD (you can see them by removing the drive cover).
There might still be a few bits of retrievable data when you are done, but unless you are an international superspy, the effort required would not be worth it to anyone. Once you are done, be sure to take the remains to an electronic waste facility for safe disposal.
Did you find this article helpful? Before you take a blowtorch to that old hard drive, leave us some feedback below!
This article first appeared on Oct. 31, 2022, and was updated on Sept. 26, 2024.
