Simply deleting a file or re-formatting a hard drive does not securely erase the files from the drive. They can still be recovered using data recovery tools, including free ones. When you delete a file it is simply "un-linked" and in what is called "free space" and exists on the hard drive until those particular sectors of the file have been overwritten. In this video, I will show you how to securely wipe a hard drive to make recovery of any of it's contents virtually impossible. I recommend doing this before disposing of any hard drives or selling your old computer. I use a completely FREE program called Eraser, which is commonly believed to just shred individual files, but it can actually wipe entire drives, partitions, etc.

WARNING!! I AM NOT RESPONSIBLE FOR ANY UN-INTENTIONAL LOSS OF DATA OR MONETARY DAMAGES, USE AT YOUR OWN RISK!

Eraser Program: https://eraser.heidi.ie/