5 steps to wipe a computer hard drive
Authored by a Symantec employee
You want to donate or recycle your old computer gear, but there’s something you have to do first — wipe your hard drive. That means clearing out all your personal information.
You may think that’s not a lot of stuff, but your old devices probably hold a ton of information. Your medical records, browser history, login info for your bank account, past emails — all that information about you that accumulates on a device.
It’s not enough to simply delete old files. Why? The delete button doesn’t actually delete.
Your personal information will be retrievable on a computer’s hard drive unless you take steps to wipe the hard drive clean. If you don’t, the files are there for the taking. Anyone with recovery software and bad intentions could access them and put your privacy and the security of your personal information at risk.
How to completely wipe a hard drive
Follow these steps to ensure you’re truly wiping your hard drive clean. They’ll help keep you from passing on or losing your documents, photos, passwords, financial information, and personal data when you say goodbye to your old device.
Step 1: Back up your hard-drive data
Before you wipe your computer’s hard drive or do a factory reset, make sure to back up all of your information to your new computer, an external hard drive, or a web service.
Backing up your data regularly is a smart way to keep your data safe. Hard drives can crash, get lost, stolen, or encrypted by ransomware software. The best defense is to make sure all the data is backed up safely and frequently.
You can back up your data on thumb drives or USB flash drives. But keep in mind these are small storage devices and may not accommodate all the data from your PC. External hard drives can offer more storage. You can also transfer your data to another laptop or PC.
“Cloud backs” are another option. They’re safe and one of the most convenient ways to store data. Here’s how it works.
First, you create an account and complete the initial setup. Next, you enable the storage of your data to the cloud — a network of remote servers. There’s no physical location for the backed-up data. So the risk of it getting stolen or destroyed by things like floods or fires is mitigated. Plus, the files are encrypted. That makes it difficult for cybercriminals to access or steal your information.
Step 2: Don’t just delete files from your computer
You might think moving your documents to the trash or recycle bin and emptying it will do the trick. Maybe not. This action appears to delete the files, but often leaves them where they were, hidden from view. Most data recovery programs can actually recover these hidden files.
Here’s why. When you empty files from the trash or recycle bin, the file name or the reference to the deleted file is erased. The computer can no longer see the file.
This means the space the file took up on the laptop or PC is no longer reserved for that file. But the file is still in the hard drive. It will stay in the hard drive until its location is given up for a new file to be stored in that exact location.
Data recovery software is capable of rebuilding the file header. This makes it possible for the computer to see the file again.
Here’s the risk. When your files are not deleted completely from the hard drive, cybercriminals can run data recovery software to access your deleted files.
Law enforcement agencies use data recovery software to access deleted files from confiscated computers. Cybercriminals can use the same tools and techniques to commit identity theft.
Step 3: Use a program to wipe your drive
Special software programs can permanently erase your hard drive. There’s little chance you can get any data back. Similarly, no one else will be able to use data recovery software to recover your files.
Most programs run a low-level format that overwrites all the deleted files with zeros and other incomprehensible data. This makes it impossible for data recovery software to recover the files.
DBAN is a free data destruction program* that completely erases files on a hard drive. This includes all personal files, operating systems, and installed programs.
It’s smart to use a program to wipe your device. Most products offer proof of erasure. Some even provide information about what was done to the drive and its data. This helps when wiping a company laptop or PC.
Step 4: Physically wipe your hard drive
If you want to double-ensure your hard drive is wiped, you can take additional measures. For instance, you can physically wipe the drive. Just remove your hard drive and take a rare earth magnet to it. Another option? Physically dismantle it with a screwdriver.
A rare earth magnet, like the neodymium magnet, can be used to deform the metal plates in the hard disk. This makes it unusable. One warning: The magnets are powerful and can cause physical harm if used incorrectly.
A safer method might be using a screwdriver to dismantle the pieces of the hard drive to make it useless.
Step 5: Do a fresh installation of the operating system
There’s another way to completely rewrite over the whole hard drive. That’s by completing a clean installation of the original operating system that came with the computer. This can be especially important if you’re giving the device to someone like a friend or family member.
What are the risks of not wiping my hard drive?
As the line between the real world and digital world blurs, it’s smart to understand how cybercriminals work. A security product like Norton Security Premium helps protect your personal PC files, financial information and your family’s devices. But when you discard your device without properly wiping the hard drive, you run the risk of losing your data.
Cybercriminals value your personal data — such as your email address, passwords, Social Security number, driver’s license details, and credit card information. They could sell the information on the dark web.
Cybercriminals can buy the information and launch cyberattacks to commit other kinds of crimes like identity theft and extortion. They could open bank accounts in your name, purchase items with your credit card information, or take out loans and default on them, leaving you with the consequences.
Thieves also look for private and confidential information. This may include non-disclosure agreements, personal photographs, private chat conversations, and other details you may not want to expose. If a hard drive wasn’t wiped clean, cybercriminals could retrieve this information to blackmail the owner of the content.
Types of data deletion
No matter what kind of data you had on your computer before you decided to donate or recycle it, it pays to play it safe.
Remember, deleting your files from the recycle bin or trash doesn’t mean the file is gone from your device. It only means its location is available. Data recovery software can easily find those files in your hard drive.
Here are a few ways to wipe your hard drive like the pros and avoid the risk of someone accessing your old data.
Short for Darik’s Boot and Nuke, DBAN* uses a random number generator that wipes and overwrites everything on the drive several times. Every file that has been deleted now has the new number assigned to it. This makes it impossible for data recovery tools to access it. This tool is useful if you plan to sell, donate, or recycle your computer or laptop.
2. Destroy the hard drive
A sure way to completely destroy the hard drive is to make it physically impossible to access the disks. This can be done by dismantling the pieces of the hard disk with a screwdriver and using a hammer to scratch and mangle the disk. The goal is to make sure the disk will not work when it is loaded into another hard drive. A powerful rare earth magnet can also be used to destroy the platter in the hard drive.
How Norton Utilities can help wipe your hard drive
Your PC is likely packed with personal files. It’s wise to keep all that information secure and private. Norton Utilities is a handy tool that keeps your PC running like new. It fixes common issues that slow down or crash your PC. It also frees up space by finding duplicate files and unused applications.
It’s commonplace to store personal files on your PC. Now it’s easy to keep your digital life private. Safely dispose of personal documents, so no one can access them. Think of it as a digital shredder. Norton Utilities helps keep what you do on your computer private. It can permanently erase all record of your computer and web-based activities to help protect your privacy.
It also safely disposes of personal documents permanently and renders them inaccessible. Most of all, it maintains your digital privacy by erasing your recently opened files and website browsing history.
There’s a lot you can do to help protect your personal information if you take the right steps before disposing of your old computer.
Our best protection. One low price
Norton Security Premium helps protect up to 10 of your Windows PCs, Macs, Android smartphones or your iPads.
Disclaimers and references:
* The inclusion of websites, links, or programs here does not imply endorsement or support of any companies, materials, products and/or providers listed herein.
Symantec Corporation, the world’s leading cyber security company, allows organizations, governments, and people to secure their most important data wherever it lives. More than 50 million people and families rely on Symantec’s Norton and LifeLock comprehensive digital safety platform to help protect their personal information, devices, home networks, and identities.
Copyright © 2019 Symantec Corporation. All rights reserved. Symantec, the Symantec Logo, the Checkmark Logo, Norton, Norton by Symantec, LifeLock, and the LockMan Logo are trademarks or registered trademarks of Symantec Corporation or its affiliates in the United States and other countries. Firefox is a trademark of Mozilla Foundation. Google Chrome and Android are trademarks of Google, LLC. Mac, iPhone and iPad are trademarks of Apple Inc. Microsoft and the Windows logo are trademarks of Microsoft Corporation in the United States and/or other countries. The Android robot is reproduced and/or modified from work created and shared by Google and used according to terms described in the Creative Commons 3.0 Attribution License. Other company names and product names are registered trademarks or trademarks of each company.