How to 'shred' digital files and make sure they're permanently deleted

Here's what file shredding is, why it's important, and how you can do it.

The importance of shredding
Antivirus suites
File shredders
The choice is yours

The importance of shredding

Shredding physical documents is an important step toward securing your identity and other sensitive information, especially regarding financial and legal matters. The same practices should be carried out when it comes to computers and virtual data. Throwing away an important document with your personal information plastered in the header is similar to right-clicking on an important PDF file and moving it to the recycle bin. It's not a good idea.

The problem with deleting files this way is if someone else gains access to your PC, they will have the opportunity to retrieve the data through the use of specialist software. It's important for consumers to protect themselves from their data falling into the hands of others — passwords, contact information or even bank cards. Merely deleting files or formatting your hard drives and reinstalling Windows will not remove all references to old data.

To solve this problem, we recommend "wiping" your hard drives using software to write random data on connected storage and remove all references to the old data. The same goes for shredding files, but instead we're restricting the random write to the file location in question and not the entire drive, which is ideal if you simply wish to delete a few files and not reinstall your entire OS.

Whether you plan to sell your desktop or laptop, or you simply wish to better bolster your own protection, it's really easy to shred important files.

Antivirus suites

It's highly likely your chosen antivirus suite will have a feature to shred files securely. Depending on the software at hand, the way you go about launching this tool differs between available brands. The best part about using your antivirus package is there's no need to download and install more software to shred files. It's worth noting that some companies may require you to pay for an optional download.

The following antivirus solutions feature file shredding functionality in some form:

Avast (opens in new tab).
AVG (opens in new tab).
McAfee (opens in new tab).
Norton (opens in new tab).

If your antivirus suite doesn't have this option, or you'd like to try a dedicated piece of software to handle file shredding, we've got you covered with some great alternatives.

File shredders

These programs are either specifically designed to shred files or have some sort of related functionality built in.

BitKiller
CCleaner
Eraser
Moo0 File Shredder

BitKiller

BitKiller is an open-source suite that can not only handle the destruction of files and folders but can easily take on an entire storage drive. It's also portable, for use on removable storage, which means it can be run from a USB stick without the need to install anything on the target PC. It's incredibly straightforward and simple to use, too, especially with version two.

There's also the option to use Gutmann algorithm, for a total of 35 passes and additional security. It's secure but time-consuming, so be sure to go and fetch a hot (or cold) beverage while it carries out the file deletion. Much like Moo0 File Shredder (more coming up on that tool), BitKiller lets you drag and drop files into the app. It's absolutely up there as one of the easiest shredders to use.

Download BitKiller

CCleaner

CCleaner (opens in new tab) is one of the best tools for checking what files are taking up valuable space on your PC. The suite also handles file deletion with random overwriting, so if you already have it installed you don't need to install another tool to carry out shredding. CCleaner need to be configured to handle the secure deletion of files, but once that's set up you'll be good to go.

To access the file shredder in CCleaner, you'll need to go to Options > Include to add any folders or files you wish to have CCleaner securely delete on its next system scan and delete pass. The easiest way to manage this feature (if you want to shred files on a regular basis) is to set up a folder where you can dump files you wish to permanently delete. Then you can simply add this folder to CCleaner and it'll delete everything within the folder.

Here's a quick look at how to add individual files, and folders are added in a similar fashion:

Hit "Add".
Choose "Browse" under "File". (For folders, simply choose the top option.)
Select the file for CCleaner to shred. (You can't do multiple selection here.)
Hit OK.

Choose "Cleaner" in the side menu.
Hit "Run Cleaner."

Having a dedicated shredder folder will allow CCleaner to clear out and shred files contained within on each cleaner run. That makes it real easy to delete files normally through Windows and shred important or sensitive information using the suite.

Download CCleaner (opens in new tab)

Eraser

Eraser (opens in new tab) is incredibly easy to use. In fact, you control pretty much everything through Windows Explorer context menus. Need to shred a file quickly? Simply right-click on it, choose Eraser and then the use erase option. If you'd like to go slightly more advanced, firing up the software can allow for scheduling tasks, much like CCleaner but without any user interaction. You just add a folder or two, and the software handles the rest.

The default erase method is Gutmann, which overwires files 35 times. While secure, this means the process can take a little time to complete.

Download Eraser (opens in new tab)

Moo0 File Shredder

Another great leightweight file shredding tool is from Moo0. It's small, highly secure and it gets the job done without issue. A great feature of Moo0's shredder is the ability for you to drag and drop files into the software to have it carry out the process. Forget having to set up automated tasks and specific folders for shredding.

The suite can be configured to remain on top of all programs, to make accessing it more convenient, and there are four rather humorous options for shredding: Vaporize, Into Ashes, Extra Carefully and Shred Once. The first is the most thorough option based on the Gutmann algorithm, and Shred Once is a light but fast attempt to overwrite the file.

Download Moo0 File Shredder

The choice is yours

What software you use to shred files is entirely up to you. A good way to see how well your choice works is to run a file recovery program, such as Recuva (opens in new tab), and then have it search for a test folder you used to shred some files. If it can detect and recover your deleted files, you'll know to either use a more secure setting or opt for an alternative shredder suite.

Rich Edmonds was formerly a Senior Editor of PC hardware at Windows Central, covering everything related to PC components and NAS. He's been involved in technology for more than a decade and knows a thing or two about the magic inside a PC chassis. You can follow him on Twitter at @RichEdmonds.

8 Comments

Interesting, thank you! Could you go into a bit more detail over how these would differ from when you wipe your PC using the Windows 10 reset/refresh tools - Is it wiser to use these to shred your files before using Windows 10 to wipe everything when selling your old PC for example?
When you look at the files/folders in Windows Explorer what you're seeing is more-or-less the Table Of Contents for that drive partition. The files themselves are stored in small pieces on the drive partition, and this sort of TOC records where the pieces of each file are physically on the drive. When you delete a file the only thing that goes away is the TOC entry -- the pieces of the file are still there until something else is written in their physical space. That's why all of those deleted file finding or recovery apps work. Overwriting every bit of disk space clears that data, but it takes a long time, so most erasing apps just overwrite the parts of the disk where a file or files are stored, though some also have the option to overwrite free space. Because the last piece of a file may not fill up the small section of the drive [cluster] where it's stored, the space that's not used can contain old data from a previous file -- some erasing apps can oversrite those small spaces too. On a regular hard drive overwriting storage space both deletes the old data & writes new -- with an SSD that same thing takes two separate operations. Since having to clear a space before you can write to it would make SSDs slower, they use Trim processes that automatically clear the storage space formerly used by now deleted files *before* you need to write fresh data there. That said, it may not be possible to completely erase all of the data stored on flash RAM, & some drives have a special command or feature to delete everything, but how well that works [& if it works] can vary. When you write to a regular hard drive the write heads float above the spinning platters on a cushion of air. There's a little bit of wiggle room where a head might write a track a little to the right or left instead of dead center. When you overwrite part or all of the disk that means that there might be old data left on those fringes, especially if say the data was written to the right & the head was to the left when it overwrote that data. Actually reading any data left over that way requires an expensive specialized lab service, but nonetheless, most erasing apps give you options to run multiple passes, to better ensure that nothing gets left behind. Now, to your initial question about rest/refresh tools... wherever they write files they overwrite any data that was stored there previously -- wherever they leave any disk free space, old data may remain. While it's not guaranteed the most accurate way to tell what's still there, you can always run one or more file recovery apps to see what deleted files & file fragments still remain.
You forgot Bitdefender Internet Suite.
I wish this feature was built in to Windows 10 recycle bin (at least for enterprise edition).
Can any of these programs be intructed to just shred everything placed into the recycle bin?
I think there is a built-in command on Windows that just does the same. It is used in BitLocker to erase encrypted data, and just does the same even when encryption is not active.
Shredding individual files doesn't actually work against advanced file recovery methods.
SSDs spread the wear by writing blocks to least used slots. This means even modifying an existing file will typically write the file in other cells than their previous location, and mark the previous location as now available for new use.
Even on HDDs, SMART can remap clusters silently if they start to fail. Resetting SMART could then give access to files you believed you erased safely months or years ago. So just overwriting a specific file with random data a few times will do nothing to help remove the previous data if the drive performs these writes somewhere else physically.
The only solution is to force the drive to write random data in every unused slots of the drive, ensuring the slots that contained the file gets rewritten as well.
And no need for 3rd party utilities, this is exactly what the Windows cipher /w command does.
I suspect the Windows 10 reset with drive wipe procedure (when you select that you want all data erased for safety) performs the same thing.
Unfortunately these procedures also mean you'll wear all unused slots of the drive by several passes (3 typically), reducing their life in case of SSDs.
If I have a bitlocker encrypted drive, and format it for re-install, then my files should be safe. A person would need to discover the encryption key before scanning for old files. Since I re-bitlocker the new install, so they would actually need to discover 2 encryption keys (assuming the act of re-encryption doesnt 'blow away' any old files??) This would be too much effort for anybody intersted in my files, since I am no CEO etc...

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