When you delete a file on a Windows based computer, or even if you format the computer, the files aren't really gone. What windows does is take off the label or 'header' of the file to let Windows know it can use the space for something else.
That is why in many cases you can get files out of your recycling bin, or you can buy a program that recovers deleted files. The information is still there, now the label, or nametag is gone. If you want to really delete a file, you need a program that deletes files entirely. There is a method for this kind deletion and it is the Department of Defense
standard.
When you delete your internet browsing files, and when you delete those old and fuzzy pictures that aren't quite in focus, they're not really gone. Yes, even some files that might not exactly be appropriate. If you're not worried about what you do on the computer, who else has access to your computer? You may not do anything inappropriate on your computer, but a family member, coworker, friend or neighbor might.
When you delete something, you typically want it to be gone forever. Enter the program that I seem to be using more and more for whatever ails my computer,
Ccleaner. There is an option in Ccleaner called 'Wipe Free Space'. When you run Ccleaner it warns you that if you check this option, it can take considerably longer to 'clean' your system. It is worth the extra time in my opinion. Below is a screenshot of the option grayed out at the bottom.
You can change the settings Ccleaner to wipe the free space on your system to run 1, 3, 7, or even 35 passes on your free space. The highest setting can take a considerable amount a time run, so be warned.
You files should definately be deleted after you run it this way.
If you are going to sell your computer, or sell a hard drive on Ebay or even give away your computer, I would recommend using a utility that will wipe the entire drive. There are many utilities that will do this, but use
Active @ KillDisk. It is easy and quick to use. It is not hard to configure and this should take care of your files from the most curious of people besides law enforcement.
There are many ways to make sure a drive and it's files is unrecoverable. One that almost everyone has access to, and is 100% reliable is the hammer!
Just simply smash the hard drive till you hear the platters inside the drive shatter. I recommend you where saftey goggles and follow all safety procedures while using the hammer. Also, I personally use the claw end of the hammer, it seems to get the job done quicker.
