File shredders are special computer programs used to destroy computer files beyond retrieval.

File shredders are identical to paper shredders that are used to shred unwanted papers that contain sensitive information.

File shredders destroy any given file by overwriting it several times with random and meaningless data. Several overwrite passes are used to ensure that the deleted file will not be recoverable.

File shredders use special algorithms. Some of these algorithms have become de facto standards for shredding computer files.

File shredders are not very well-known programs, but those who know these programs and are aware of the importance of security and privacy use shredders extensively.

Shredders are used by several parties like military forces and private organizations to get rid of computer files permanently and to ensure that these files will not fall in wrong hands.

File shredders are not widely used by individuals,  but they are very useful softwares that can provide security and privacy at a very high level if used properly.

Shredders usually provide several methods that users can choose from based on situation. More overwrite passes mean more security and privacy, but more computer resources are used at the same time.

Ultrawipe is a nice file shredder that you can download it at following link and use to shred your unwanted files and free spaces of the hard disk (hard drive):

http://www.snapfiles.com/reviews/UltraWipe/ultrawipe.html