When securely erasing data from a Hard Drive, with Eraser etc, do you actually lose disk space? ?

I am uncertain whether disk space on you hard drive is actually lost or not after securely erasing data with overwriting.  In other words is your hard drive actually harmed with decrease storage ability.

6 Answers

  • 1 month ago
    Favorite Answer

    When you delete a file using Windows, the file itself is not actually removed from your hard drive.  Rather the pointer that stores the location of the file is moved to a list of "free" space.  At that point Windows can no longer find the file.  But the data is still there.  Eventually the file will be overwritten with new data.  At that point the file no longer exist.

    When you use a program like Eraser, what it does is go through the list that Windows has of "free space". and writes garbage to every location on the list.  That overwrites an deleted files so they can no longer be retrieved. 

    Doing that does not increase or decrease the available space on the hard drive.  It just overwrites any old data that still exist in the free space with garbage.  It does not in any way harm or decrease storage ability.

    Every single location on your computer's hard drive has something stored on it.  Either valid information or garbage.  All Eraser and programs like that (such as Boot and Nuke) do is to overwrite all data - or if you select, the whole hard drive - with garbage.

  • 1 month ago

    you are rewriting the whole drive and checking it for zeros, it will put strain on the drive but any space loss is negligible

  • 1 month ago

    No, you gain space.

  • Lv 7
    1 month ago

    no, but the only reason to "securely erase" is if you are giving the computer to somebody else.

    otherwise, you are just wearing out your storage drive more quickly, and adding unnecessary extra time to the process of deleting files.

    but yhe process does not decrease usable area. it basically just ensures that deleted files are gone forever, which is historically a bad idea. you should ALWAYS wait 30 days at least before removing stuff from your Recycle Bin...

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  • 1 month ago

    Imagine your hard drive is like a large island where each "file" is like a buried treasure chest. Each time you add a file, you dig up a spot on the island, draw a map to that spot and mark an X on a master map to say that spot is used.

    When you "delete" a file, your computer doesn't actually dig up that treasure. It just destroys the treasure map and erases the X on the master map.

    Somebody could just randomly start digging up unmarked spots on your island and find that treasure, so it isn't really gone. 

    The only time it is actually removed is if you are burying a new treasure. You look at the master map and find a spot that doesn't have an X. As you dig, if you find something there you just destroy it and bury your new treasure in its place.

    The thing an erase utility does is to actually dig up the old treasure, destroy it and replace it with random junk instead. You can still use that area for new treasure, just like you could before, but nobody can get your original treasure by randomly digging because it's actually not there anymore.


    No, it doesn't change your available free hard disk space. 

  • Adrian
    Lv 7
    1 month ago

    No, secure erasing should not affect the amount of storage space. However, if the drive is faulty and has lots of questionable disk sectors, a secure erase with write to every sector and firmware in the drive may detect more bad sectors and re-map them, eventually running out of spare sectors. At that point, you get visible bad blocks to operating systems, like Windows. Further to that point, no reason to secure erase the drive, it is past its useful life. Destroy the drive with a hammer or drill and be done with it...

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