When I was way younger I was very involved in the latest PC hardware and data security subjects. I always tried around how I could recover corrupted or deleted files from a hard disk and how to wipe data storage in a way so the files could not be recovered after files got deleted or hard disks got formated. I tested how I could restore deleted media like movies or pictures with photo recovery software on the hard disk but it was also possible to do photo recovery from an SD card. In the end, it was often possible to recover data, maybe not 100% but a good amount of data.
I thought that an issue like this would have been surely addressed by now, but I was so wrong. This problem still exists and maybe with even greater risks than ever. In this article, we want to create awareness about the risks but also help users to handle their data the right way.
Why is any of this important? Because you either want to dispose of devices if they no longer work or if you want to resell used products, like laptops, that include hard disks, and you want these to go out of your premises without your data still on them. Especially when you think about what sort of sensitive data we just keep around on our devices, we really need those files to be gone and unrecoverable in order to avoid people using personal data, such as professional or financial information. Some people might be buying used laptops only with the goal of finding sensitive data that they could use to blackmail the previous owners or gain access to accounts.
Why is this even possible?
You can download software for recovering lost files on hard disks without much trouble and there are even good ones that you’ll be able to use without even paying anything for it. Though I have to say, it’s easier to recover deleted files from old technology hard disks, like the classic mechanical ones with magnetic attributes. These are not that common anymore in new laptops but I’m sure you can still find those when you’re looking to buy used computers. If you merely delete files here or use the quick formating options for clearing the whole HDD, files have a high likelihood of being recoverable without issues. Maybe large or complex files will be corrupted and not readable, but photos or videos can usually be used. In order to avoid this, you’d need to overwrite these parts of the data storage, which is a more lengthy process than just wiping it empty.
What are the odds?
A recent test done by IT experts for a German information television show outlined that out of ten used laptops bought by the testers, five would contain recoverable data, and two of these contained critical files like financial information, personal ID card copies and even a written authorization to handle all transactions of someone’s bank account. Depending on who gets their hands on this data and whether or not malicious intent was the driving force behind the purchase, there is a certain risk that can no longer be mitigated once the devices have been shipped. This sort of risk is critical for personal laptops but even more so for devices that are used to process business information and might contain client data.
How about modern technology?
For newer technology, like solid-state drives (SSD), this is not the same thing. If you’re deleting files on an internal SSD, it’s likely to use the Trim feature and it will not only remove the data but also overwrite the previous information with empty cells to make sure no information could be recovered. This is however not necessarily the case for external SSD storage units. External drives that are connected to your PC with a USB cable in order to access or store data are not using Trim and files you delete are likely to be recoverable later on. This is also true for other external storage solutions like USB thumb drives or SD cards.
What to do before you sell your old laptop?
No matter if you want to sell your devices or prepare to dispose of them, it’s in your best interest to make sure there is no recoverable data from your left on the HDD or portable SDD. Fortunately, with modern versions of Windows, this became an integrated function and you no longer need to get third-party software just to turn your data unrecoverable. In case you want to keep any or all of the data, make sure to make a backup before you tackle the next steps. How to wipe your data safely on Windows?
- Make sure you have admin rights
- Open Windows Settings
- Click on the option “Update & Security”
- Navigate to “Recovery”
- Find the option “Reset this PC” and click on “Get started”
- Choose “Remove everything” and never go for any quick process
- If asked, do not go for “Keep my files”
- Review all the changes and confirm with “Reset”
The computer will then take a while to process everything but will continuously inform you about the current status and tell you once everything has been done. Once everything has been deleted and fully wiped, you just leave the device. As soon as you try to boot it up, it would present you with the Windows provisioning dialogue and begin to prepare the OS for a new user. You don’t want to do that, you can let the new owner do these steps.
If you want to format single drives that don’t host your operating system, you can also use the Windows feature for formating in “This PC”, but make sure you never go for the quick format process.
Verify your work
If you’re not confident by what Windows has done in this reset and wipe wizard, you can also verify yourself what files there still might be ready for someone to recover them now. For that, you need software that is built to recover lost, corrupted, or accidentally deleted files such as Piriform Recuva (CCleaner), Stellar Data Recovery, Disk Drill, or any free software you trust. Install the software of your choice once you have finished the provisioning of a fresh Windows installation and see if you can find anything hidden. If everything is fine, you can start over with the steps above and begin the reset and wipe of the system, to prepare to sell the product off to someone else for a second life.
If you enjoy videos more than reading, you can also check out the tutorial below by Mike from Mike’s Unboxing channel.
YouTube: How To Prepare A Windows 10 Computer For Sale With Full Erase (Mike’s Unboxing)
Photo credit: The feature image has been done by Benjamin Lehman.