Friday, December 16, 2016

hard drive - How do computers permanently store data?






I've heard several times that when you delete a file, even after removing it from the Recycle Bin, it is still permanently stored on your computer and can be accessed by the likes of police professionals if needed. How does this work without effecting disk space?


Answer



This data isnt stored strictly speaking.


What happens when you delete isnt EXACTLY the computer going and wiping all the data out. What actually happens is that the computer forgets that that file exists(delete file system entry for that file). This means that if another file comes in that needs harddisk space, it might be stored over the old file. If this does not happen, several tools can scan the hard disks to undelete such files.


You can try this yourself by googling undelete. You will get many tools which will be able to recover deleted files.


This is why, when trying to securely delete files, people use specialized tools which actually go over every bit of hard disk space used to store those files and fill it with all 0s or random junk.


You can find more info at http://www.howtogeek.com/72130/learn-how-to-securely-delete-files-in-windows/


No comments:

Post a Comment

hard drive - Leaving bad sectors in unformatted partition?

Laptop was acting really weird, and copy and seek times were really slow, so I decided to scan the hard drive surface. I have a couple hundr...