Many of those who have deep computer science education and experience realize that when you delete a file from a file system, you are not always purging it completely. In-fact, the quickest way to delete a file has proven to be simply unlinking it from the file structure reference. It’s quicker because you do not have to re-write (meaning clear) the entire section where your file is located. When your file is unlinked, it is allowed to be overwritten in the future.
So if you ever delete a file and cannot restore, you can use this technique to scalp out your undeleted files. Pretty basic, pretty simple, much more base level. Enjoy!