How to Completely Delete Files From a Computer
Most people do not think about it, but when they delete a file from their computer, it is not destroyed. The computer deletes certain key information about the physical location of the file from the disk directory on the hard drive. The file is still sitting there on the disk and can be recovered by someone with the knowledge and the right equipment. Knowing this, one may be asking about now, "is there a way to completely delete files from a computer?" The answer is yes.
One method of deleting files in a way that makes it impossible to recover them is using a large magnet to degauss the hard drive. This realigns the magnetic fields on the disk and effectively erases every scrap of data that was ever stored there. The drawback to this method is that the disk is completely erased, including system files and operating systems.
Today, it is possible to purchase software that is capable of overwriting an entire disk to cover the data with random number sequences that means nothing. One pass of this software will normally render files impossible to retrieve for civilians. Government agencies and police forces can still get the data off the disk. It takes up to seven passes with this type of software to completely overwrite all files and make them irretrievable. This method also overwrites the entire disk, destroying data that may be valuable or wanted to be kept.
The newest technology involves a file shredder program that randomizes the data in the deleted files at the time of deletion. These are still physically present on the disk, but the data is so scrambled that no computer is able to make sense of it. This method allows one to completely delete files from a computer without completely erasing the entire disk.