If you are thinking of getting rid of your computer, either because you are going to sell it or because you are going to dispose of it, it is important that you delete all the information that is recorded on the hard disk. Contrary to what many users tend to think, formatting or reinstalling the operating system does not completely remove the information stored on the internal storage. The reality is that your data is still available, even if it is not visible from the file explorer.
In this guide, you will find the necessary steps to completely erase a hard drive without leaving a trace. We also clarify some doubts that may arise about this topic.
Why Resetting a PC not Enough?
Resetting Windows is not the solution to delete your data. Usually, when a computer is sold, whether it is a desktop or a laptop, it is decided to reset the operating system. However, this process does not delete all the data on the hard disk and a user with advanced knowledge could recover it very easily. Why is it not enough to reset the computer?
When we format a hard disk or recover the computer, we are telling the operating system that the previously occupied space can be used again for writing files. Therefore, the pre-formatted files are still there waiting for new data to be written to them. Only when this happens, i.e. when the new file is stored on top of the old one, is the information permanently deleted.
This can be a real headache in some situations. For example, suppose a company decides to renew its fleet of computers and gets rid of the old ones. To prevent access to the company’s sensitive data, it applies a format to the drive. If no one adds files back to the computer, all of the company’s information will still be available for later retrieval. Fortunately, some solutions can help you erase a hard drive. This is known as low-level formatting.
What is Low-level Formatting?
A low-level format is a much more complex process than that carried out with a traditional format. Although it is essentially performed in the same way, it is responsible for completely removing all data. It is also known as physical formatting and is applied by manufacturers before distributing their computers. In addition to protecting privacy, low-level formatting has other advantages:
- It returns the disk to its factory state.
- It organizes the hard disk and optimizes it.
- It solves magnetization problems.
Removing All Data from Hard Disk
Method 1: Use a Tool from Windows
If you want to delete information from a hard disk, you can use a tool called HDD Low-Level Format Tool. It is a very simple application that does not even require installation. However, it runs on Windows. Therefore, you should use it only if you are going to erase a secondary disk or a removable memory stick. After downloading its executable from its official website, do the following:
- Open the application and select Continue for free. This is its free version, although some limitations apply.
- Select the drive you want to format and the one you want to remove all the information from.
- Click Continue.
- Open the Low-Level Format tab and select the Format This Device option.
When the process is finished, the information on your hard drive or external memory will be gone forever.
Method 2: Use a Tool Outside Windows
The above method is ideal for quickly formatting a drive at a low level from the operating system itself. But what if you want to remove all the information from the main drive? In that case, you must use a tool that runs outside the operating system. A highly recommended one is DBAN. To use it, you will need:
Once you have these three resources, follow these steps:
- Connect the USB drive to your computer.
- Open Rufus.
- Select the USB drive in Rufus and choose the DBAN ISO you downloaded from their website.
- Create a bootable drive with DBAN.
- Restart your computer and boot from the USB drive.
- When DBAN loads, activate the manual mode with the Enter key.
- Select the drive you want to completely erase.
- Press the F10 key to delete all information on the drive.
Before proceeding, please note that your computer will no longer have an operating system. Therefore, we recommend that you create another bootable drive to install Windows or Linux. This will be necessary only if you are going to sell the computer or if you want to keep it. If you are going to get rid of it, you do not need to install an OS on it.
Method 3: Physically Destroy the Hard Drive
Destroying the platters should be your goal to remove the data. Both methods involve an investment of time. In the case of method 2, some advanced knowledge is required. If you intend to dispose of your computer, a good option is to physically destroy the hard drive. This involves damaging the drive in such a way that it is unrecoverable. To make sure this is the case, it is advisable to beat it until the platters are shattered. Another option is to use sandpaper or drills to drill them. Keep in mind that if the aim is to make the data completely inaccessible, it will not be enough to scratch the disks a little.
If it is an SSD disk or a USB memory stick, physical destruction is much simpler. In most cases, it will be enough to hit the drive repeatedly to break the memory cells.