Deleting Files?

Question

In movies and criminal tv shows and series, when dealing with investigations in which they search the suspects' computers, sometimes we see that the computer specialist was able to restore deleted files. How is this possible ?
Lets say I save my word files and pictures for example in 'my documents' folder or on my desktop. When I delete them and empty my "trash" the files are deleted from 'my documents' or my desktop. And if I open my computer, then my 'C' folder/drive and 'my documents' from there, the files aren't there either.
The same with programs that are installed in the 'program files' folder. When I uninstall a program its files are deleted. Of course some programs leave a few files sometimes, but if you delete them they're supposed to be... well, deleted right ?
Is every file or program incoded in my comuter and saved in my 'windows' or 'system32' folders as well and THAT'S where computer experts find them after altering them to readable files ?

I recieved many great answers. Thank you all :) I do have one more question though regarding what many users answered. Can I write over files that weren't completely deleted without using special programs ?

I mean, how do I make my files are deleted ? Doesn't my comuter save files in random memory "cells" ? How do I make sure it writes over the files I want deleted without using special programs to do that for me ?

Answer 1

Even though you have deleted those files, their footprint is still on your hard drive, electronically and magnetically. And there's lot of recovery software that can pull the delete information off your hard drive and back to life.

That's why it's important to have a very good hard drive cleaning utility that will erase your deleted files and clean, or wipe, empty hard drive space (where information was once before) repeatedly, wiping and re-wiping the deleted items so it's next to impossible to retrieve again.

You can visit Download.com and look at their privacy software and cleaning programs. I grabbed the link for you. Look for any highly rated free programs: http://www.download.com/Privacy-Software/3150-2144_4-0.html?tag=dlbc

I personally enjoy using Tracks Erase Pro by Acesoft. It erases everything that can possibly be erased, safely, and allows you to shred and customize other places on your computer to permanently delete thngs. Check them out here: http://www.acesoft.net

I hope this helps.

Answer 2

First of all, when a file is deleted on a computer it may or may not still be on the hard drive. When files are written to the hard drive, the data is written there as well as a record where the file is located. Think of when you go to an office in a big building. You know the person's name but you have no idea what floor or office number, so you look it up in the building directory to find out. Computer files on the hard drive and how to find them is in a directory (Master File Table, for example). Now when you delete a file, it's taken out of the MFT, but data is still there with no pointers to it. So, it's there but not there. Sophiscated programs can scan the hard drive without using the MFT and find data that hasn't been overwriten by another program. See, when the pointers were deleted, the space where your file was is available, and the next saved data will probably overwrite (reuse) that space. Also, programs that create content (Word, picture progs, etc) leave tracks all over the place on your computer, that an expert can probably find.

Answer 3

Wow that's a very technical question.
What happens to the best of my knowledge. Is that when you delete a file. Is that the file is not really deleted. It just frees up that space for other files. So untill some other file overrights that space the file is still there. Thus unless you run a program that will wipe those areas of data yes the files are still there. You just cant see them.

Answer 4

when you delete a file, only the reference to the file is deleted, which means the computer is saying that this part of the hard disk (where the file sits) is ready to accept data. The previous data itself is not erased, to save processor time.
When you save another file, and the system saves it on that part of the hard disk, then your previous file will be permanently erased.
But as long as that part of the hard disk is not overwritten, experts will find a way to 'resurrect' it.
...
"write over the files without special program?"
hmm... many commercial security software could do that. but if you mean only windows apps, perhaps defragmenting the hard disk could do the trick, but you wouldn't know if it were successful

Answer 5

Files are truly gone from the hard disc, only when new data is written over the old. This eventually occurs, but until then, the data is recoverable.
So if you delete a file and walk away, the data is still on the disc even though your PC is "fooled" into "thinking" it is gone.
Re-formatting destroys everything on disc.

Answer 6

The deleted files aren't truly deleted unless you overwrite them b using a file shredding program
http://www.webopedia.com/DidYouKnow/Hardware_Software/2002/Erasing_Deleted_Files.asp
Webopedia: Are Deleted Files Completely Erased?

Answer 7

To add to the answerer above me^ , CCleaner has a "secure delete" function where you can place the file or folder and it gets over-written up to 7 times.

http://ccleaner.com/

Answer 8

i have no idea. i guess they use some kind of special computer program to restore files. basically, it's difficult to restore files when you permanently delete them.

Answer 9

its very easy my dear... just use the "recover my files" software.. you can find it on www. phazeddl . com ..

Answer 10

um. i also have no idea. needo if ever someone gave you the best answer share it to us also. ;)