A disk editor can also uncover deleted data by displaying the information that is stored in each segment of a hard drive or diskette. If your desktop, floppy, or portable computer gets into the wrong hands, files that you thought were long gone can be easily uncovered. Accordingly, be very careful before passing your computer on to anyone in or out of the office. Those who sell their computers should also remember that data erased from hard drives is often recoverable. A more dangerous and common situation is the ability of diskettes to transfer deleted file data.
Many firms recycle diskettes when passing files to clients and colleagues.
The same delete limitations that apply to hard drives apply to diskettes, and an industrious recipient can resurrect files that once were on a floppy but were supposedly deleted. Another scenario is old e-mail messages, which may, for example, be preserved on backup media. There are several methods to delete files for good. The easiest way is to reformat the hard drive or diskette. Users must perform a full format, however, which overwrites each sector of the disk and hard drive.