Here's a little tidbit that most computer users don't realize: Deleting files on your computer system does not actually delete files from your computer system.

It's true. Deleting files actually only removes visible references to the file, while the actual data remains completely intact. This explains how "undelete" programs and utilities can function, they simply look for the existing data and restore files by associating this data with the previously deleted file name.

If you wish to retrieve files that have been previously deleted, (and even removed from the "Recycle Bin") there are a number of utilities available that can do just this; they can be purchased from any retail store that sells software.

So how do you actually delete files that you do not want anyone to be able to retrieve at a later date?

While this may not concern the average computer user on the typical day, there times that you may very well want to completely remove files from your system, and for good reasons. For instance, how do your truly delete a file that contains sensitive and confidential data, such as a financial spreadsheet? Of even greater concern, when the time comes to sell your existing computer, how so you insure that the new owner will not be able to retrieve all of your old files, passwords and other sensitive data that have been stored on your hard drive over the years?

Because deleting files simply marks the corresponding portions of your hard drive as "free space" that is available for use, until new data is written to the exact same spaces, the deleted file is easily retrievable. Even after overwriting the previous file's data, sophisticated tools exist that can still retrieve much, or even all, of the old file. In fact, files are not actually considered "beyond retrievable" until the same space on the hard drive has been written and overwritten at least six times.

Unfortunately, you typically have no control over where your system writes information on your hard drive, and thus cannot forcefully overwrite files yourself. To achieve this level of control you need to use special software utilities. While many such deletion utilities exist, and are available in software stores, PC Magazine has authored a program called Shred 2, which is available for free.

Like most such utilities, Shred 2 allows you to delete directories on your hard drive, and can also "clean" all of the currently unused areas of your drive. This is exceptionally useful when you realize that all of your hard drive's currently "free space" likely contains a wealth of data from previously "deleted" files.

Rather than simply removing references to files, this form of deletion actually writes, and rewrites, data over the same areas of your drive numerous times (up to 30) in order to truly destroy all trace of the deleted files.

While this can be a time-consuming process for your computer, and is not something you would ordinarily need to do on a regular basis, when you want to truly remove particularly sensitive data, this is your only practical option. More significantly, whenever you sell a computer that you've used, such methods are the only way to insure that the system's new owner cannot retrieve your previously deleted files.

To download a free copy of Shred 2 Click Here

NOTE: If this links should change in the future, you can always just visit pcmag.com and search through their "Downloads" section to find the Shred 2 utility.

From a practical standpoint, the easiest way to use Shred 2 in order to protect your sensitive data is to simply delete all files as you ordinarily would, which actually moves them to the Recycle Bin. You can then simply run the "Shred the Recycle Bin" option to destroy these files on a regular basis.

This approach will not consume much of your time, and certainly not the hours that are necessary to "Shred" all of the free space on your hard drive; a process best done only when selling a used computer.