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How do I prevent someone from recovering files on a hard disk - if i delete one file in a hard disk directory it must not able to recoverable by any recovery software.

I need some simple technique to do this.

os-windows 7

karel
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Suresh E
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  • CCleaner offers a free way to shred deleted files in the `Recycle Bin` it can also wipe the free space on your hdd if you want. – Ramhound Jun 21 '13 at 10:55
  • In general you first need to be sure that the file is "erased" vs simply being hidden in the Recycle Bin or whatever, then you need to overwrite the physical space. Some folks believe you must overwrite several times, but that's only necessary if you're hiding black helicopter stuff. @JourneymanGeek has what are probably the best specific suggestions. – Daniel R Hicks Jun 21 '13 at 11:30
  • You haven't said exactly what OS you're on, and what file system you're using. So, if you are using a Mac, for example, using 'rm -P' from a Terminal window might be what you're looking for. – JamieJag Jun 21 '13 at 11:53
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    @DanielRHicks: the multiple overwrite delete process was useful with lower disk densities - a lot of people follow the old guttmann paper blindly. With a few exceptions, a single erase is enough for modern HDDs. I'm a bit confused with the state of SSDs since I've read papers for both greater and lesser data reminance in SSDs – Journeyman Geek Jun 21 '13 at 12:00
  • @JourneymanGeekn - The problem with SSDs is that they "wear out", so disc microcode attempts to avoid writing to the same location repeatedly. Even if you open the file for update the changes may not go back to the same physical locations. – Daniel R Hicks Jun 22 '13 at 11:39

2 Answers2

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Its probably useful to know the difference between a secure delete, and a regular one - a secure delete overwrites the sectors that were used, while a regular one merely marks it as unused.

When I need a file level secure deletion on windows, I tend to use eraser (for a GUI) and sdelete (for scriptable or command line use) , on windows and shred on linux to delete files.

Naturally until you're sure this works, it wouldn't hurt to check with a recovery software to see if it actually worked.

Journeyman Geek
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  • in sdelete we can use batch file for perform this operation right? – Suresh E Jun 21 '13 at 12:02
  • I believe you can - just need to supply it with the right arguements – Journeyman Geek Jun 21 '13 at 12:04
  • I use Windows laptop. I'm about to sell my laptop. Now I simply already formatted my drives except the OS drive. Can I still use sdelete so no one can recover the already deleted data on my empty drives? I mean there is nothing on remaining drives except the OS drive. – Vikas May 17 '22 at 18:08
  • If you took a look at the page for sdelete - it'll wipe empty space, which is what you're asking for I believe – Journeyman Geek May 20 '22 at 11:51
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Personally I use Axcrypt (free) to encrypt single files and folders. Axcrypt has an option to "Shred and Delete" which asks if you want to "overwrite the file with random data and permanently delete it?"...BAM! Now that's what I'm talkin bout! :)

f1assistance
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