But that is not always sufficient, especially if files need to be deleted that contain data that should under no circumstance be recoverable. Think of financial information, private pictures and videos, copies of official documents, and other private data.

FileKiller is a portable Open Source software for the Windows operating system to delete files permanently. This is achieved by overwriting the files with random data, blanks or Ascii code so that the overwritten files become unrecoverable.

The method can be used on conventional hard drives, not solid state drives who handle writes to the drive differently.

filekiller

Files can be added in the main interface by clicking on Select Files. This opens a standard file browser. One, or multiple files can be selected for secure deletion. It is unfortunately not possible to select directories, which means the software is not suitable for deleting files that reside in many different directories.

Software alternatives for this operation are Blank and Secure, or Eraser.

Back to FileKiller. The left sidebar offers configuration options, including the number of iterations and the type of data that is written over the file sectors of the hard drive. It usually is enough to reduce the iterations to one, and fill the space with blanks or random data.

Recovery software like Recuva or Pandora Recovery can be used to confirm that the deleted files have become unrecoverable.

FileKiller could use an option to add all files of a folder and its subfolders automatically. Another helpful option would be a context menu addition to send files or folders directory to the program.

The secure file deletion software has a size of about 50 Kilobytes. It is compatible with most 32-bit and 64-bit editions of Windows. Downloads are provided at the project’s homepage at Sourceforge.

It happens to be that Eraser has another nice feature which is pretty unique if you ask me. You can access the program Eraser Verify from the start menu or by starting verify.exe in the Eraser directory. This little program lets you erase single files with different algorithms to make it impossible to recover by normal means. Every step is shown in a hex editor which means that you can verify on the fly that the file becomes unreadable.

The process itself requires minimum user input. Select the algorithm or keep the default one, select the file that you want to securely erase and click on Erase. The file will be shown before Eraser begins the process to show you how it originally looks like. If you click continue in that step Eraser will start its work. You see how the file looks after every step which means you can verify that the file information have been deleted.

I was thinking of something different though. What if I want to keep my hard drives for now but make sure that deleted data can’t be recovered by any means ? I tried and ran some file recovery programs such as Recuva and it showed thousands of files that were still referenced on my system although they have been deleted before. I think that this is a privacy problem and decided to look for a way to delete all file information on the unused part of my hard drives.

I decided to use Recuva first and see how many file information it would find. After that I would run a program named Eraser which I will use to clean the unused disk space of any deleted file information and finally run Recuva again to see if this reduced the amount of files that could be undeleted from my system.

Testing my Hard Drive with Recuva:

Recuva found 33720 files on my hard drive f: that could be undeleted. This is a large amount of files.

Running Eraser:

After right-clicking the central pane I was able to create a new task. The first option was unused space on drive which is the default option in the menu. I selected the f: hard drive from the list. Eraser was showing my newly selected task in the central pane and I had to right-click that task once again and select Run from the context menu. It took two and a half hours to overwrite all the data on my 100 gigabyte hard drive.

Testing the result with Recuva:

Recuva found one file on drive f: Everything else was not found anymore which leads to the conclusion that this is an excellent way to erase file information that exists on the unused space on your hard drives. This is probably not enough to erase it for the big boys if you know what I mean but every amateur should have problems getting information about those files.