The simplest program I found that securely erases files (and is free) is a program called "eraser". You can download it from: http://www.heidi.ie/eraser/. This program will allow you to securely delete any file that you have on your computer. There is detailed help available for this program, if you have any questions they are probably answered here.
Once downloaded and installed it will add an extra menu item to context menu for the "Recycle Bin", this item is "Erase Recycle Bin". When you want to securely remove files from your computer, drag them to the recycle bin, and then right click on the "Recycle Bin", and select the "Erase Recycle Bin" option. When the dialog appears asking you if you are sure you want to erase the contents of the recycle bin, select yes.
If you are finding that it is taking too long to erase all your files, you may change the options. You do this by clicking the "Options..." button in the confirmation dialog. By default the options are the most secure, and you should not change them unless it is taking too long.
If you want to delete email, web history, and other information you should read the Help that is included with this program.
If for whatever reason you are unable to download eraser, Windows has a built in erasing tool called "cipher". This tool erases the free space on a computer's hard disk. This is needed because when a file is deleted, the space used by that file is marked as free, but the data is still stored on the hard disk. This program goes through finding all of those areas that are marked as free, and overwrites them with random data. As a result, if you want to securely delete a file, you have to delete it using the recycle bin inside Explorer, and then run the "cipher" program.
The "cipher" program is a command line program; this means that you have to use the keyboard to run it and not the mouse. To run this program you follow these steps:
- Start a command prompt window:
- From the start menu, select the "Run.." option,
- At the "Open:" prompt that will appear, end "cmd" and then click "OK"
- A black window should appear, and it should start by saying "Microsoft Windows XP"
- Type "cipher /W:c" and press the enter key. (Don't type the "" though!)
- The program should start; it will take a long time to run.when it is finished, all deleted data will be unrecoverable.