In Windows, if you delete an important file, even from the Recycle bin, it’s still entirely possible to recover that file as long as it doesn’t get overwritten between its deletion and your attempt at recovery. That’s because the file is never truly deleted and Windows is just told that the space the file occupies is available to write over when needed. In this case, a free tool that you can use to recover data is all that’s required.
But this is obviously not good if you want to permanently delete a personal or private file because anyone could just try to recover it. Once a deleted file has been overwritten, it’s very difficult to recover and more professional methods would be needed to get any readable data back.
There are various ways to overwrite deleted files. If you sell or give your drive to somebody else, it needs to be completely wiped so nothing is left that can be recovered by the new owner. You can also erase the deleted data off a current drive by wiping all its free space. Then there’s the method we’re talking about here which is to completely overwrite and wipe the file or folder as you go.
This method is the quickest and most secure as the files are erased immediately and not left in a recoverable state until the next time you decide to wipe the drive’s free space. Here are 10 free tools that can securely erase or “shred” your files making them unrecoverable. All tools were tested in Windows 10 and 7 64-bit.
Important Note: Permanently deleting files is something that should be used with care as once the file is deleted and overwritten, you won’t be able to get it back, even with recovery software.
WipeFile is a portable only program so is also useful for your USB toolkit. It supports 14 different erasing methods ranging from a quick single pass zero fill up to a full 35 pass Gutmann erase. A single random pass should suffice in most cases. Individual files or whole folders can be added to the program. Something that is very useful is an editable file mask for folders so you can filter what gets erased by file name or extension.
The default mask of * will delete all files in the folder whereas a mask of *.doc will shred the Word documents and ignore all other files. Double click the folder entry to change the mask. In the settings, you can create a context menu or “Send to” menu entry and send files to the program via right click, create a user defined erase string (used with WipeFile erase methods), and enable logging. The .NET Framework 4 is required for Windows 7 users.
HardWipe has several different types of data erasing, such as wiping Recycle bin contents on selected drives, wiping a drive’s free space, wiping a drive or volume completely, or shredding files and folders. Unfortunately, the portable version is no longer free so the software needs to be installed. An annoyance is the inclusion of advertisements inside the main window although it’s not overly intrusive.
Click File Data on the left and browse for the files and folders to securely delete. Shift or Ctrl is supported for multiple selections. There are 6 wiping algorithms ranging from a single random or zero pass up to 35 passes and an option to rename the files up to 9 times to lessen the chance of recovering the filename (default is 3). A speed mode can help system responsiveness on long operations and the system can be auto powered off after a long wiping operation has completed.
Permadelete has a pretty user interface and is quite basic but most users don’t need loads of options anyway. Files and folders can be deleted by either dropping them onto the window or using the two browse buttons provided. After selecting files for deletion, a box pops up asking how many passes the shred process will run. The default of one pass of random data can be changed in the options.
It’s worth noting that Permadelete does not shred files on SSDs and relies on TRIM and garbage collection. This has the effect of wiping the data after a period of time anyway while decreasing the wear and tear on your drive. If you must shred a file on an SSD immediately, use something else in this article. Permadelete has portable and installer versions, is open source, and requires .NET Framework 4.5+ for Windows 7 users.
4. Alternate File Shredder
Alternate File Shredder is another program that can permanently delete files and also wipe free drive space if you need it. The number of times you can overwrite a file can go up to a massive 100 passes, although only the most paranoid users will find it useful. Overwriting can be with random data (recommended), with zeros, or with a predefined pattern of your choice. Changing the pattern is done from the Options window.
You can add files and folders (including the Recycle Bin) by either drag and drop or by using the buttons in the toolbar. Extra security options are available such as shredding file names and original file sizes. An interesting feature is a binary viewer where you can look at and directly edit files with the ability to add, remove, insert, or even replace specific bytes in the file.
5. File Shredder
File Shredder is more of a permanent erasing solution because it needs installing and there’s no portable version, but it does have some useful functions which could make it worthwhile. Erasing algorithms include simple 1 or 2 pass, DoD 3 pass, secure 7 pass or the Gutmann 35 pass method. There’s also Explorer integration which can directly erase the file/folder immediately or add it to a queue to be shredded later on.
Files and folders are added to the list using drag and drop or the add buttons on the left. The default shred method is DOD 5220.22-M, which is three passes consisting of zeros, ones, then random data. Go to Shredder Settings > Algorithms to change it to something else. A shred free space option is also available if you want to remove previously deleted files from the drive entirely.