Earlier I wrote about how to recover deleted file from your hard disk. But today I am introducing the opposite task. I hope this article will serve a different taste. If we want to delete a file permanently then we all may have a miss concept that using Shift+Del key we can delete the file permanently. (You might also like to read how to Recover Deleted Files from your Hard Disk.)
According to a survey by British Telecom it has been learnt that most people does believe that deletion of data means the removal of the data from computer. But in real that does not happen. So you may ask what happens actually and how to delete a file permanently?(Read also how to make a folder inaccessible and un-deletable).
The scene at the background
Every time you store any file or data,it allocates a space in your hard disk and when you want to delete theme in the most popular way(Shift+Del) it appears that the files or data has been removed from your hard drive memory. But the data are not removed from the disk memory, actually the pointer which point the data storage location is deleted and the information about the data and its location is lost. So it appears the space which was allocated by the data is free. Later the location is over written by a new data. So there is a chance to recover the deleted data until a new data replace it. So if you want to delete erase your data and want to save from other hand then you should be confirmed about your data that you deleted are still recoverable or not. In this post I discussed the matter how to delete file permanently.
There are two basic way to delete permanently the data from your computer
1.If you format your disk drive then the data is deleted permanently and the space become totally free (Not quick format).
2.You can also use some method that overwrite the data you have deleted.
There are two main method to overwrite a data
- The Guttmann Method:A best secured process of data wiping has introduced by Peter Guttmann in his paper “Secure Deletion of Data from Magnetic and Solid-State Memory“.In this process the data is overwritten 35 times to make it unrecoverable.But it is a time consuming way.
- US DoD 5220-22.M:Based on the United States Department of Defense recommendation 5220-22.M,Though it is little bit less secured compared with Guttmann method,it is faster than the earlier.
While the Mac Operating System has a built-in data wiping tools then in Windows there are many software available for data wiping.Eraser is a free open source program for Windows 95, 98, ME, NT, 2000, XP, Vista, Windows 2003 Server and even DOS.
Data wiping in Mac
To delete a folder in Mac just move it to trash and select ‘Secure Empty Trash’ from .Finder’ menu.
There is another inbuilt utility ‘Erase Free Space’ in utilities folder in Mac that scan the hard disk for unused space and erase them using The Guttmann Method or US DoD 5220-22.M.
Usage scenario of Eraser in Windows
Download and then install the application Eraser. Download Eraser and install it. Run it in your windows. A simple box will appear.
You can select the files and folder by choosing it from windows explorer and drag and drop in the ‘Eraser’ list or by Copy and paste in the list or simply from the ‘File’ menu of the application ‘Eraser’.
Now you have to choose one of the specified methods
- The Guttmann Method (Default)
- The US DoD 5220-22.M Method
- The Pseudorandom Data Method
In Pseudorandom Data Method all passes will be random data and they are highly incompressible.
You also can schedule your removal method in the tool Eraser.
Another method that wipe the data of a complete drive
Darik’s Boot and Nuke (DBAN) is a free open source program for windows(virtually for any machine) wipes the entire data of the drive when it runs. So you should very careful when dealing with this tool.
From the DBAN about page:
Darik’s Boot and Nuke (“DBAN”) is a self-contained boot disk that securely wipes the hard disks of most computers. DBAN will automatically and completely delete the contents of any hard disk that it can detect, which makes it an appropriate utility for bulk or emergency data destruction.
After downloading DBAN write it to any CD or DVD. Now boot from that and when it prompt for “Boot” enter ‘autonuke’
The last and greatest way to erase your file or data permanently
- Open out the hard disk
- Expose the disk by unscrewing the casing.
- Smash them on the floor
Now your all data is totally secure. Hmmmm !Is not a secure process?
I think you would like to share something with us in the comment section.