It’s not secret that when you delete files or folders in Windows, they’re not actually erased; the space they took up is simply marked as “available for use,” which allows the files to be recoverable until they’re overwritten with new data.
There is a utility built into Windows (even XP Pro and vista) that will overwrite all the free space on a hard drive, insuring any files you’ve deleted stay dead. Launch a command
prompt and type cipher /w:X (X is
the letter of the drive or partition you want
to wipe). be patient; the process can take a
long time if you have a lot of free space.
