How to really delete files ?

[nForc3r]

.... random 1 and 0 are written on hard disk.

This is the key

[Gavo]

I use evidence eliminator V6, it can multipass/scrub files so the data is totally gone

i read data can still be recovered after 1 pass.

But i dont use it for that, it has a 1 click total system clean to get rid of all the junk windows keeps

[Jesse]

You can use File Shredders, those tools will convert one file in to thousands of small pieces then it just delete it.

I use Pointstone shreddar. Comed with the following options:
Single Pass: The fastest, but least secured of the data destruction algorithms. Your data is overwritten with zeroes in a single pass.
Triple Pass: Triple Pass consists of two complimentary overwriting passes followed by a random pass. This is an extra security measure that should prevent any particular recovery program retrieving your data.
U.S. Standard, DoD 5220.22-M (7 passes): U.S. Department of Defense specifies a seven pass extended character rotation overwrite algorithm in the DoD 5220.22-M specification. This Total Privacy shredding method conforms to these overwriting standards as well as method 'd' of the Cleaning and Sanitation Matrix.
U.S. Navy NAVSO P-5239-26 (RLL) (3 passes): This shredding method conforms to the U.S. Navy standard and uses three passes - one flush, one specifically patterned for RLL and one random.
U.S. Navy NAVSO P-5239-26 (MFM) (3 passes): This shredding method conforms to the U.S. Navy standard and uses three passes - one flush, one specifically patterned for MFM and one random.
U.S. Army AR380-19 (3 passes): AR380-19 is the data destruction level specified and published by the U.S. Army. This procedure calls for 3 overwriting passes, one random and a character with its compliment.
German Standard, VSITR (7 passes): The German standard calls for each sector to be overwritten with three alternating patterns of 00 and FF and in the last pass with AA.
Russian Standard, GOST P50739-95 (7 passes): GOST P50739-95 is the purge required by the Russian Federation. This procedure calls for a single pass of zeroes followed by a single pass of random characters.
Peter Gutman (35 passes): Peter Gutman suggests methods for ensuring that the recovery of data can be made as difficult as possible for an attacker by offering the 35 overwrite pass algorithm. This algorithm is slow, but extremely reliable.
Bruce Schneier (7 passes): The Bruce Schneier method offers a seven pass overwriting algorithm. The first with all ones, the second all with zeroes and then five times with a cryptographically secure pseudo-random sequence.

[Cojba]

Peter Gutman (35 passes) I think this guy can really delete files

Tnx for your responses, I wasn't thinking that there is the whole science abt this when posted first question

[vorazeal]

its like when you delete files from your PC it does not actually get deleted, its still stored inside your HDD.

It only gets deleted if other files overwrites that location of the HDD.

So if i have 100 MB HDD, i delete 50MB movie, O.S will show 50MB free, but that file is still present in your HDD.

Now if you copy another 50MB movie into same drive, new movie overwrites the old file present in HDD and now its impossible to get that file back.