Data Destroyer

It can be used for secure deletion of all files on a disk (but it cannot be used to wipe a disk including unused space). To securely delete (a.k.a. "purge") a file (on a disk or on any writeable magnetic medium such as a pen drive, a.k.a. a memory stick) means to delete the file by overwriting the data in the file many times (before removing it from the file system) so that the data which was in the file cannot be recovered by any means. Several overwrites (at least) are required for security, since just one may leave electronic traces of the original data which can be detected by very sensitive equipment designed to do this.

It is well-known that when Windows "deletes" a file it does not actually destroy the contents of the file but rather simply unlinks the file from the file directory system, leaving the contents of the file in the disk sectors. This data will remain there until the operating system re-uses those sectors when writing new data. Until the old data is overwritten (and this may take months or longer) it can be recovered by programs that read disk sectors directly, such as forensic software (so called because it is used to obtain evidence in criminal investigations and also in legal discovery). If you wish to make sure that information in files containing confidential information (such as financial data, company plans, proposals, etc.) can never be recovered after deletion then you need a program such as this.

Beware of data removal programs that are claimed to delete files quickly. The only way data can be removed permanently is to overwrite it (on disk, not just in the disk cache) several times (not just once), and this takes time (more or less, depending on the speed of the hardware involved).

Data Destroyer can be used to wipe securely all files on a disk, but it is not a disk-wipe program, because it cannot be used to overwrite the free space on a disk (which may contain data left by previously deleted files).

Data Destroyer can purge multiple files in multiple folders in a single operation. You can tell Data Destroyer not to delete a purged file so that you can inspect the contents with a hex editor (or re-use the file in testing). And you can request an estimate of the time required for any purge operation (if too long then the time required can be reduced by reducing the number of overwrites).

Data Destroyer can:
• wipe a single file
• wipe all files in a folder
• wipe all files in a folder and all files in its subfolders
• wipe a specified subset of files in a folder and (optionally) in its subfolders
• wipe all files (as above) whose file dates are before a specified date
• wipe all files in selected subfolders (or in selected subfolders of a folder)

When a file is purged the slack area is also purged. (The slack area is the space on the disk, if any, in the final cluster of sectors which follows the end of the contents of the file. This might contain data from a previous version of the file.)

This software checks for possible errors in user input, and is designed to minimize the chance of accidentally purging a file that you wish to keep. It is even possible, in a multiple-file purge operation, to confirm the operation on each file before it is purged.

Another feature of Data Destroyer is that you can get an estimate of the time required to perform a purge operation. Secure deletion of many files may require some hours, and if you did not have an estimate of the time needed before beginning the operation you might get worried, not knowing how long it still has to run.

Data Destroyer will permanently delete files from any writable magnetic storage medium, which includes hard drives, floppy disks, ZIP drive disks and memory sticks. It is not suitable for erasing data on CD-ROMs (unless writable). The program wipe specified files only, and cannot be used to wipe an entire hard disk.