BitKiller

In certain cases, deleting files is better than letting them fall in the wrong files. Unfortunately, the operating system just marks the data as free space, instead of actually deleting the files. As a result, the information can be salvaged with specialized recovery utilities. If you want to make sure that your files will stay deleted, then you should definitely try BitKiller. This simple and lightweight application can erase any files and overwrite them until there is nothing left to recover. It provides several shredding methods and it is very easy to use.

BitKiller is absolutely free and you can use it straight out of the box. Instead of going through an installation process, you only need to extract an executable from an archive and run it. It is compatible with most Windows versions and it doesn't have any special requirements.

The user interface displays strictly what you need to shred files, so you don't have to spend any time studying its controls. The application can be aimed at single files or entire folders, using different browsing options. The targeted files and folders are displayed in a list and you can remove individual items if you change your mind. Loading data on the application's interface and clicking a button is sufficient to erase the files and replace the information with random data.

The available shredding methods are located on the left side of the user interface and you can select one by clicking its corresponding radio button. Besides replacing information with random data, the application can also replace everything with zeros or overwrite the files several times. If you select one of the DOD methods, the application will make 3 or 7 passes when overwriting data. Furthermore, you can opt for the Gutmann method, which overwrites files 35 times.