How to Secure Erase an SSD or HDD Before Selling It or Your PC
If you’re selling or gifting an old PC or just the internal drive, you should securely erase your SSD or hard drive to prevent the next person from accessing your files. Needless to say at this point, simply deleting a file doesn’t make it disappear completely. The operating system removes the pointers to the files and leaves every bit of it until the drive needs space for new data and overwrites it. But that can take years and never happens if you have a lot of free space.
You might think that just resetting Windows 10 or 11 with the option to delete your files enabled would remove all your personal data, but it’s not, we’ve done the tests to prove it. I was preparing to donate an old Windows 10 PC, so I used the built-in Windows Reset feature,[すべて削除]clicked. This will remove all files and leave the factory default installation of the OS.
After the reset process was complete, my personal files were practically wiped, as was all the software I had installed.However, after installing and running EaseUS Data Recovery Wizard Free (opens in new tab)I found all the old files using the Find and Undo File utility. To prove my point, I restored a file called mypasswords2.txt that was in my Documents folder and was able to read everything in it.
Even if you sell your computer or bare drive to the nicest person, you can’t believe they don’t know the deleted files they can recover. I’ll explain how and how to do the same for hard drives as the process is a little different.
How to securely erase an SSD
Secure erasing an SSD is different from performing the same process on mechanical hard drives. The best way to wipe a HDD, detailed below, is to use a program that writes random data to every sector several times, leaving no remnants of old files.
This brute-force overwrite method does not work on SSDs. All SSDs have a limited number of write cycles, so overprovisioning is used to extend the life of the drive and replace blocks that fail over time. So at any given time there may be 5% or 10% of blocks unavailable to the OS. Overwriting the entire drive will not affect these blocks which may contain important data.
What you need is a utility to get all the data. Some of his SSD manufacturers provide secure erase utilities for free, and some motherboard BIOSes (see how to enter the BIOS) have built-in secure erase functionality. However, a cheap and universal way is to use Windows 10 or 11’s built-in diskpart utility with the command: prompt. You can also use this method if the SSD you plan to erase is your computer’s boot drive. Method is as follows.
1. If the drive to be erased is the computer’s boot drive: Boot your computer from the Windows 10 or 11 installation disc (For disc creation instructions, see How to perform a clean install). If the disk you want to wipe is not a boot disk, you can do this wipe from within Windows without having to boot from the installation disk.
2. Start Command Prompt. If you booted from the Windows installation disc, Press Shift + F10 Show a command prompt over the installer. If you are using a regular installation of Windows, search for “cmd”, right-click on the top result and select[管理者として実行]Choose.
3. come in disc part. The prompt will be DISKPART>.
Four. come in list disk Shows a list of all disks connected to your PC and their numbers. If you only have one drive, it will be disk 0.
Five. come in select disk [NUM] Where [NUM] is the disk number, probably 0. For disk 0, type: select disk 0.
6. come in clean everything. After a few seconds or minutes, you should see a message that the process is complete.
The drive is safely wiped. If you plan to give the computer to someone else, he can go ahead and reinstall Windows on it. I used “Erase Everything” to securely erase his SSD on a PC that I had donated to charity, and now I can’t see the deleted files using EaseUS Data Recovery.
TRIM does not securely erase SSDs
Some experts claim that TRIM-enabled SSDs (most modern SSDs) don’t need secure erase because deleted data is erased in the background. Unfortunately, you cannot expect TRIM to erase all blocks, even if you try to force it using the Windows 10 or 11 drive optimization feature. I took out the drive that I erased with Windows 10 reset function, defragmented the drive, and EaseUS Data Recovery was able to restore my sensitive files.
“This is an expected result from experience,” said Mike Cobb, Director of Engineering at DriveSavers. “TRIM doesn’t always work on all devices. This is why TRIM is unreliable unless validated on the system and actual drive model.”
DriveSavers is a leading data recovery service that retrieves deleted data from client SSDs and hard drives using a unique set of specialized tools. For businesses with a particular interest in secure erase quality, DriveSaversData erasure verification service (opens in new tab),” the experts check to make sure nothing can be recovered.
How to securely erase a hard drive
The best way to reliably wipe an old mechanical hard drive is to overwrite it with dummy data multiple times. There is a popular freeware app called DBAN (Darik’s Boot and Nuke) that writes to every sector using a safe sanitization method.
DBAN is its own boot environment (no OS required), so you can securely erase your computer’s boot drive without ejecting the drive and plugging it into another PC. However, if the hard drive you want to erase is not your boot drive, you need to be very careful when using DBAN to avoid accidentally erasing the wrong drive.
1. download DBAN ISO file (opens in new tab).
2. Burn ISO to USB Flash Drive (It only takes 20MB of space) so it will be bootable. The easiest way to do this is Rufus (opens in new tab), a free USB burning tool. Start Rufus,[選択]Click to select ISO,[開始]Click.
3. Boot from DBAN USB drive. A menu with a blue background and gray text appears.
Four. press enter Enter interactive mode. It takes 1-2 minutes for the system to detect the storage device. A menu screen appears, showing all drives and other options.
Five. select the drive Want to. Use the J and K keys to move up and down, and press Space to select a drive. “Wipe” will appear next to the drive.
6. Choose how to erase your drive Press M if you want something other than the default DoD Short method. DoD short is a three-pass version of the US Department of Defense’s 5220.22-M wipe process. The first pass overwrites all sectors with zeros, the second pass overwrites them with ones, and the third pass uses a random pattern.
Standard DoD 5220.22-M erasure is 7 passes. The more passes, the longer the secure erase takes. The DoD short method should be fine for most people, so you can skip this step if you agree.
7. press F10 Start the process. Depending on the number of passes, drive capacity, and speed, this can take several minutes to several hours.
When complete, DBAN displays a message that all mapped drives have been erased.
The hard drive should now be safe to transfer or sell. If you give away a computer with a hard drive, be sure to reinstall the operating system.