i will sell my PC.how do i permanently erase all sensitive data from the hard disk, leaving no readable trace?

Answer 1

You can!

Standard Way:
Delete first everything on your harddisk that is sensitive.
But don't delete it normal. Use a SHREDDER program. You can get this for free on www.download.com

The main problem is not to erase this data, the problem is to find ALL sensitive data. Usually it is easy. You delete (always with the SHREDDER) the Folder "My Documents". Then you delete the Folder "Program Files".
Then delete with the same way the Folders that you created by yourself.

Usually is in the Folder "Windows" no personal data. Don't forget to delete the Folders "Temp" in Windows and on the Root.

That should be enough.

Highest Security:
If you want to be 1.000.000% sure then do this:
Download an Harddisk eraser tool. It will format your harddisk 7 times (CIA Limit for secure formating) and overwrite every time every cluster and bit with with an single bit+ and bit-. This is the best way and makes the harddisk absolutly clean.
For this the Harddisk must be a Slave harddisk and you start the HD-Eraser from the other Harddisk. You can find this tool as freeware on the same Downloadpage as I said before.

Answer 2

(EDIT) xenobyte72 is incorrect, NO Correctly scrubbed Hard drive can ever be read from again. IT IS BLANK but is can be reused. But you can NEVER read any scrubbed data from it. The University mentioned below along with others are trying Electron microscopes and other devices but NONE work so far!

To Completely Wipe your Hard-drive clean use the following.
Recommended by the University of Harvard Computer Science Division.

"Darik's Boot and Nuke (CDR/CDRW Version) - [2006-03-19 | Freeware | 1.9 Mb | DOS | 7914 | 4.87 ]
Securely wipes the hard disks of most computers."

The direct link is currently at:
http://dban.sourceforge.net/

USE EXTREME CAUTION and label this disk! Only insert in a PC you want to wipe clean of ALL DATA!

NOTE:
Most Hard-drives are shielded from external magnetism so unless you crack open the case and rub an extremely powerful magnet on the disk, that wont do any good. Floppy disks are unshielded and you can erase them with a magnet, but not a shielded Hard-drive.

Re-Formatting your Hard-drive will NOT erase any information. it only clears the FAT File Allocation Table, it does not erase ANY files as most people think.
Give me a hard-drive that has just been re-formatted and I can get EVERYTHING off it and copy to a NEW drive with NO PROBLEM at all.

Answer 3

Formatting the disk is not enough. There is special software around that will erase everything on the disk for good (see some of the previous answers) but what will also help is

format the disk, put some DVD movies on the harddisk (this will erase all previous info) then erase those and then the next owner will not find anything except maybe a movie.

Answer 4

This is near impossible, aside from completely destroying the hard-drive. The ram and cache won't retain anything when there is no power supplied. You would be well advised to just hold on to your hard-drive, you can get a case from pc-world or maplins and convert it to an external drive. Read the instructions carefully.

The military use special software which overwrites the whole hard-drive with random 1's and 0's but incredibly this has been undone by some clever boffins who, thankfully, are few and far between. This is available to the public and can probably be sourced using CNET.com.

Answer 5

You could wipe the disk by formatting it. However I think computer experts can still recover some or all your data if they have the know-how. The only way to be 100% is to replace the hard disk. However for most cases a format will do.

Answer 6

use a stay-linux CD called Darik's Boot and Nuke CD. that's an operating equipment that runs off of disk and writes "0's" over each sector of your troublesome stress. receive the .ISO (see elements) and burn it as a bootable disk. Reboot your pc with the blistered disk on your stress besides from CD. A blue exhibit with classes will arise even as it boots. purely form "autonuke" to erase each thing on your troublesome stress - and the disk will do some thing. The receive is loose and open-source, and it extremely works extremely nicely :)

Answer 7

Even if you format the hard drive there are still ways to read the disk. Its just harder to do so. My sugguestion is to buy a new hard drive, and destroy the old one. If someone really wanted to read the old data on a formated hard drive there ways to do so because the old magnetic coding bleeds out into the space between tracks.

Answer 8

if you are selling it to a first time user ,then you can do a normal format,you can do this with either the xp disc,or you can use a windows 98,me start up disc(easiest way)
you can get all the start up discs from http://www.bootdisk.com/,and once downloaded you can execute the program and it will make the floppy start up discs
depending on the make of your hard drive you can go to the support section on thier site and you can download utilitys to format drives
good luck

Answer 9

you mean porn? lol formatting allone wount do the trick. most 3rd partie disk mngment tools will do the trick. ive alo got a little file which is called dellpart. get in contact with me through the link below and ill send it 2 u. it's also a handy engineer tool i normally use it to get rid of linux partitions

Answer 10

If it is really sensitive, I suggest destroying the hard disk. It is worth it