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Deleting Files the Secure Way: Q & A

Why isn’t just deleting a file enough?
Many believe that when a file is deleted, it is permanently erased. In actuality, the data within the file still remains on the drive; this is because of how the Windows operating system saves and deletes files.

  • When you save a file, your PC stores the name of the file in a file allocation table. The data that actually makes up the file is saved directly on the computer’s drive.
  • When you delete a file, your PC removes the file reference from the file allocation table, but the data still remains on the drive. The space occupied by that data is marked as free space and is available for overwriting by other newly saved files. But until another file’s data is saved over it, the deleted data remains.

Even though you can’t see the file, someone using easily available software tools can recover the file and view its contents. To securely erase files so that they can never be recovered, a data wiping tool should be used.

Doesn’t formatting a drive erase data?
Formatting a drive does not erase data. Formatting erases file allocation information and performs other housekeeping functions for data storage, but the process does not erase or wipe data.

How does secure data wiping work?
Data wiping tools work by overwriting deleted data with random characters.

Each overwrite pass causes the data that previously occupied the location to become less “bright” than the random data that now rests on top of it. As you increase the number of overwrite passes, the less chance there is that the data is recoverable. Some advanced methods can read up to seven layers down, which is why the U.S. Department of Defense standard is seven overwrite passes.

The DriveScrubber approach
DriveScrubber® gives you the flexibility of tailoring the patterns used in the overwrite passes and lets you select the number of passes—you can choose the Department of Defense standard of seven overwrite passes or, for the utmost in security, overwrite data up to 100 times. DriveScrubber also has a range of flexible, advanced options that allow you to pause, cancel, and resume a wipe in progress, create log files, run a final wipe of all zeroes and more.

Further, DriveScrubber offers dual protection for permanent data removal: you can completely wipe all the contents from a drive or device OR you can erase just the remnants of previously deleted files. Both options meet or exceed the standards of the U.S. Department of Defense.

  • DriveScrubber can wipe the entire drive to completely erase all data. People find this useful if they want a “like new” drive after virus damage or if they are giving away their computer or device and want absolutely no data to remain.
  • DriveScrubber can wipe only the free space to thoroughly erase the remnants and tracks left by deleted files. Existing files, programs and the operating system are all left in intact. People find this useful for regular computer maintenance and security.
iolo UptoSpeed

UpToSpeed™ is iolo's ongoing article series written by PC experts for everyday computer users. Each article is packed with easy tips and practical advice on the latest issues affecting computers to help you get the most out of your PC.






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