If you are planning on selling, donating or recycling an old device it is important to wipe it. Your devices contain lots of data about you and you don't want it to get in the wrong hands. Wiping a computer can be a pretty straightforward process if you perform it correctly.
This guide will detail everything you need to know about it to make sure it really is a stress-free experience.
Do I need to wipe my computer?
There's a multitude of reasons why you might want to wipe your computer, and you've probably already got a couple in mind. A computer owner may wipe their device for any number of reasons, including:
- Wanting to throw the physical device in the trash.
- To restore it and sell it.
- The prospect of an existing or imminent hacking attack.
- The computer has been infected with malware.
- performance is so poor that the device is unusable.
- They simply want a fresh start on the same device.
What should I do before wiping my computer?
If the information currently stored on the device you want to wipe is valuable to you – maybe you simply want this device, not your data, wiped – then make sure to back up your files before you do anything.
Wiping a computer, or indeed restoring it to factory settings, is not typically a reversible process. If your device automatically backs everything up to a cloud storage space, then it might be a good idea to double-check that's all in working order prior to proceeding with your task, and then deactivate it.
Factory resetting vs wiping a computer
A factory reset can sometimes appear very similar to wiping a computer, but there's a key difference. Factory resets restore a computer to how it was when it was bought – so any settings you have modified no longer apply.
However, this doesn't wipe data from the hard drive of your computer. In theory, someone who obtained the physical machine along with said hard drive could, if they wanted to, extract data from that hard drive.
Two ways to permanently delete the data stored on your device can be found after we run through factory resets. However, some OS developers combine the two tasks, like Apple, giving users the ability to erase hard drives as part of the factory settings restoration process.
Factory reset: a step-by-step guide
All major computer suppliers have tried to make this process as easy as possible, so here's how to do it on the most common operating systems.
Microsoft's process for restoring a computer to factory settings is essentially straightforward. There's a slightly different process depending on the version of Windows you're using, but if you have the latest model, Windows 10, then this is how you do it:
- Open the Settings menu and click on 'Updates and Security'.
- Select 'Recovery' from the menu on the left-hand side.
- Choose whether to keep your files and just delete your apps and setting preferences, or vice versa.
- Click 'next' and you will be presented with a summary of what's being deleted.
- Select 'Reset' from the next menu.
Restoring a computer with a Chrome OS to factory settings is incredibly simple, and probably the easiest operating system out of the three to manage when it comes to performing this task.
- Log out of the Chromebook you'd like to wipe.
- Press and hold Ctrl+Alt+Shift+R.
- Click on 'Restart'.
- Select 'Powerwash' and then 'Continue', and follow the instructions that appear on the screen.
- Log in to the Google account you'd like to become the new default and check to see if the factory settings have been restored.
As mentioned previously, Apple's website states that one of the steps in the process of restoring your Mac to factory settings is to wipe the hard drive and just back up your data beforehand in another location.
This means killing two birds with one stone, which is useful. Apple has detailed instructions on how to do this available online so you don't get stuck.
Total Wipeout: three options
As we've covered above, restoring the factory settings to your computer might make the device appear as if it has been wiped, but that's not necessarily the case. There have been several cases of hackers retrieving devices that have been submerged in bodies of water and still being able to extract data from them.
To truly wipe a computer, you need to heavily encrypt, shred, or physically destroy a hard drive.
Solid State Drive encryption
Most computers these days use SSDs – Sold State Drives – which are a bit harder to wipe than most traditional hard drives. Instead of storing your data on a collection of spinning, magnetic disks, SSDs uses flash memory to store data.
Nowadays, deleting a file will simply send it to the recycling bin, and even if you remove it from there, there are often still ways to recover. What this illustrates is that the data is there somewhere, buried away inside the SSD.
It's actually easier and a lot simpler to just encrypt your drive, and it has the same effect of making your data unrecoverable. Only you will know the key, and to anyone else who recovers it, it'll just look like nonsense.
Hard drives and data shredding
You can purchase data-shredding software programs that overwrite the data on hard disks a number of times over and cannot be unwritten. This can take several hours, but then again, so can destroying it altogether.
The big benefit of data-shredding is the fact you can still resell the laptop afterward without having to purchase and install a new hard drive. Apple provides its own built-in drive wiping tool called Disk Utility to help their customers permanently erase files. Instructions for how to do this on all Apple computers that use intel-processors (most models up to now) are available.
If you're using Windows 8 and Windows 10 (but unfortunately not Windows 7) then you have two methods to wipe your drive at your disposal.
One way to wipe your drive clean is to format it. Just navigate over to the 'This PC' menu via the Windows search bar, and it will pull up your drives and the folders being stored on them. Select the drive you want to wipe and click on 'format'. Here, there are different wiping options depending on whether you would like to use the drive to store new data in the future.
Alternatively, you can reset your PC and wipe the drive at the same time if you head over to Settings, then click on 'Updates and Security' (just like you would for a factory reset), click 'Recovery', and then select 'Get Started' under 'Reset This PC'. Then, just be sure to select 'Remove Everything', then 'Next', and then 'Reset'.
With Chromebooks, pretty much all your files worth keeping will be saved on Google Drive, which is cloud-based and thus not saved to the physical device. Restoring it to factory settings and not logging back in as yourself will achieve the same effect.
It might seem a bit extreme, but if you want to ensure that your data is no longer stored on a device, you could physically destroy the device's drive, be that a hard drive or an SSD.
Inside every hard drive is a collection of disks, which is where your data is stored. Smashing these to pieces, and in turn, ensuring they can't be read, is one surefire way to ensure no one else will ever see that data. Some people prefer to use acid to destroy these drive disks, but this can be a dangerous procedure if not done properly.
It goes without saying that if you do decide to do this, you must use appropriate protective equipment and it's always worth seeking advice from someone who has done this before, especially when working with chemicals.
Be warned, if you want to sell the machine, in either case, you will have to purchase a new hard drive, which might be difficult to install.