A file, once deleted, can be recovered. If it was deleted off a Windows 10 PC, its chances of being recovered are pretty high. It doesn’t have to be sitting in the recycle bin. There are file recovery utilities that can run from BIOS, without an OS, and recover files. To prevent a file from being recovered, you need to delete it securely and for that, you’ll need a third-party tool. A simpler, though limited in scope alternative is to overwrite the file yourself. Here’s how.
Prevent file from being recovered
Let’s say you created a text file on your desktop and put all your important banking information in it. You soon realized this was a bad idea, and deleted that file. This file can easily be recovered even if you format your disk, and install Windows 10 fresh. We’ll explain why later but for now, let’s get down to the fix.
In order to prevent that particular file from being recovered, create a new text file with the exact same name as it had but in a different location. Enter either false data in it, or just absolute gibberish, or place holder text. Save the file and then copy and paste it to the same location that the original file is in. Windows 10 will ask if you want to replace the file. Go ahead and replace it.
For good measure, create several text files with the same name and copy them to the exact same location. Overwrite the previous file each time. This will drastically reduce the chances of the original file with your actual banking information in it from being recovered.
Why this works?
When you delete a file on Windows 10, even when you remove it from the recycle bin, it isn’t actually removed from your system. Windows 10 simply marks it as free space and when needed, it will eventually write files to that space. Even then, the original file may still be recovered.
Overwriting the file is something that can’t be undone. When you overwrite the file, Windows 10 immediately rewrites over that space. When you overwrite it several times, the same space is overwritten several times. When it comes down to file recovery, the file that’s most likely to be recovered is the one that was most recently written which will be the decoy file.
Utilities that securely delete files do something very similar. They make several writes to the sector that contained the file that is being deleted thus preventing their recovery. You may have heard that a deleted file can be recovered, but an overwritten one cannot. This is why.
This method does have a limitation; comparable file sizes. It is very easy to create a text file, but far less easy to create multiple files of different formats that all need to be securely deleted. Likewise, those files should be comparable in size to ensure that the entire original file is overwritten. At the end of the day, you might need to use an app after all. You can try using KillDisk.