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So you want to get rid of your computer. To keep your data secure — whether it’s financial records, business information, or anything else private that you don’t want people snooping through — you’ll want to securely wipe the hard drive. This ensures that no one can recover the deleted files. However, you don’t want to wipe the operating system itself — you want to provide a fresh operating system so the computer’s new owner can use it.
Just re-installing your operating system or restoring from your recovery partition isn’t enough to guarantee that your files won’t be recoverable. When getting rid of a PC that has potentially sensitive data, you should wipe the drive to be sure your data can’t be recovered.
Why Securely Wipe
Sure, you could just delete your personal files, or even re-install Windows or use the Reset Your PC feature built into Windows 8. However, this could leave some of your personal data behind.
When you delete a file, it isn’t removed from the hard drive immediately. Instead, the computer marks the area as usable and it can be overwritten in the future. This means that your personal files may remain accessible, even after deleting them. If you’re getting rid of your PC and don’t want people accessing sensitive data — for example, tax documents with your social-security number and other personal data — you’ll want to securely wipe its storage before getting rid of it.
The process of “wiping” just refers to overwriting all the sectors on your hard drive, replacing their contents with zeroes or random nonsense. This will overwrite any data that’s been marked as deleted, but which can be recovered.
If you don’t do a secure wipe, it’s possible that people could use a file recovery like Recuva to recover sensitive files from your hard drive.
Solid-State Drives vs. Magnetic Drives
The below advice doesn’t apply to solid-state drives, provided TRIM is enabled. When you delete a file on a solid-state drive, it is deleted immediately. If your computer has a solid-state drive, all you need to do is make sure TRIM is enabled and delete your personal files — or better yet, use the Reset Your PC built into Windows 8, re-install Windows, or restore your computer’s operating system from its recovery partition.
Using a drive-wiping tool on a solid-state drive is actually a very bad idea, as the additional writes can reduce a drive’s lifespan.
Ways to Wipe the Hard Drive and Leave the OS
We’re assuming that you want to end up with a PC with an operating system installed, but one where you’ve wiped all your personal data so no deleted files can be recovered. You can do this in several ways:
- Completely Wipe Your Hard Drive, then Re-install Windows: Use a tool like DBAN (short for Darik’s Boot and Nuke) to wipe your computer’s hard drive, eliminating everything — including its operating system.
You can then re-install Windows from a Windows disc or re-install your computer’s operating system from a recovery disc the manufacturer provided. Note that DBAN will wipe any recovery partitions on your computer’s hard drive, so you won’t be able to restore Windows from the recovery partition.
- Re-install Windows, then Wipe Your Data: First, use the Reset Your PC feature built into Windows 8, restore your PC from its recovery partition or disc, or re-install Windows from a Windows disc. You should then have a clean system without any personal data — be sure to check that all your personal data has been deleted, including data on separate hard drive partitions that may not be wiped by the recovery process.
Once you have a fresh Windows system, you’ll just need to wipe all the free space. You can use a tool like the Drive Wiper tool built into CCleaner to wipe only your hard drive’s free space, ensuring that no deleted files will be recoverable.
You could try to delete all your personal files and then use a Drive Wiper tool without re-installing Windows at all, but you’re better off starting with a clean operating system to ensure your data is removed. This also allows the computer’s new owner to start with a fresh operating system.
If You Don’t Care About the OS
If you don’t care about making the computer usable for its new owner, you can always just run a tool like DBAN and leave the computer with an empty hard drive. This will prevent the computer from booting until its new owner installs an operating system.
However, this probably isn’t the best idea unless you plan to trash the computer or its hard drive. Leaving the computer’s operating system intact will make it easier for you to sell it. If you’re giving it away for free, it will result in less work for the computer’s new owner.
Do you have any other tips for securely wiping a drive without obliterating its operating system, or do you have any favorite tools to share? Leave a comment below!