Is Deleting EnoughUnfortunately, deleting a file and then emptying the Recycle Bin offers no real protection from those who want to poke around your computer. This potential security flaw is due to the way that OSes (operating systems) store data on a hard drive
As you probably know, a hard drive is divided into an enormous number of
small storage spaces called clusters. When a user saves a file to his/her hard drive,
that file occupies one or more available clusters (wherever free space is available).
Later, when a user deletes a file, the actual data within each cluster isn’t
touched; instead, the deletion command simply marks the file’s clusters, so the
system knows they are available for reuse. Thus, unless another program happens
to use those clusters to save other files, the deleted file’s data can remain on your
This is why “undelete utilities” can recover files long after you’ve deleted them. Deleting sensitive files before disposing of your PC can certainly play a part in protecting you and your data. After all, someone can’t recover a file that they don’t know about. But for an added level of security, it is best to employ a “file shredding” utility. Shredding applications, such as Secure IT from Cypherix ($29.95; www.cypherix.com), actually destroy the data in each of the file’s clusters by overwriting file data with a sequence of patterns and then deleting the file using normal means available via Windows. That way, once the utility shreds the data, it cannot be recovered.