BitKiller is a free open source program to securely wipe files and folders making them irrecoverable, this is a very tiny 40Kb application that allows you to manually select files or drag and drop them inside the wiping window, if you select a file by mistake it can be easily removed from the list with a click.
Overwritting methods include and all 0s pass, also known as zeroing, and the quickest way to securely wipe a file, a single random data overwrite method, the US DoD 3 overwrites method, the US DoD 7 overwrites and the Gutmann 35 overwrites algorithm. I could not resize the window, not a big deal but sometimes you would like to see the full path before erasing a previously selected file. If you have to select multiple files it is best to place them all inside a folder and wipe the whole folder as I was unable to add more than one file at a time holding down the typical Windows CTRL key to do that.
On the plus side the developer should be commended for explaining to the user in the supporting “Readme.txt” file that using the Gutmann method to overwrite data on a modern hard drive it is not needed even if the software includes it. There are data wiping utilities wasting people’s time giving them the false impression that the more times one overwrites a file the more difficult it will be to recover it, in reality, in a modern hard drive there is no way to recover anything after using the US Department of Defense method to wipe data, consisting of either 3 or 7 passes. As one can easily imagine the US Government will have already carried out extensive research and spent lots of money hiring data recovery experts to make sure that the algorithm they use is secure enough for secret data even against opponents with state resources, if their algorithm is good enough to stop US DoD enemies, it should be good enough for everyone.
This is very simple data wiper, idiot proof, not as complete and secure as a full suite that also erases temporary files and hard drive free space but it doesn’t need installation and you can carry it with you on a USB thumbdrive.