Need help deleting personal info on PC.. Looking to sell

Discussion in 'Off Topic [BG]' started by Nino Valenti, Dec 9, 2007.

  1. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    I'm thinking of selling a couple of PC's and I would like to delete all of my personal info. I know that when you delete files, there are still traces of these files on my PC.

    My question is what do I need to permanently delete these files. I looked on and... well, I don't know what's good. files&tag=srch

    Any help will be greatly appreciated.
  2. A drill and a new hard drive.

    On-Track recovery in Reston VA actually recovered files from hard drives from the Twin Towers after 9/11.

    Take a drill and drill through the drive a couple of times. I had a copy of On-Track and I could get files off a low level formatted drive.

    Most end users don't really have the know-how to recompile data after a low level format so you would probably be safe.

    The only true way to be safe is to destroy the drive and just buy a new one. has drives for under 100 bucks and you would have total piece of mind.
  3. Feel free to send me the pron on your old hard drive. :p
  4. irjason

    irjason In Memoriam

    Nov 17, 2001
    Louisville, KY
    Wipe the drive with DBAN and do a fresh windows install.
  5. I used my dad's sledgehammer to destroy our old hard disk.
  6. Freddels

    Freddels Musical Anarchist

    Apr 7, 2005
    Sutton, MA
    You need to completely remove the hard drive. A friend of mine does computer forensic work (testifies in kiddie porn trials) and he can get info off a drive even after it's been wiped and reformatted and whatever. His advice is to remove the hard drive and if you don't want the info, then to break the disk up into very little pieces with a sledge hammer. This is the only way to ensure that the info safe.
  7. HollowBassman


    Jun 24, 2007
    Hancock, MD
    This is what I used.

  8. RWP


    Jul 1, 2006
    I know you are trying to save the OS and keep the units working, but don't take the chance. Hose the drives.
  9. Just remove the harddrives, save them in your home, and buy new ones for the computers to sell. Hard Drives are fairly cheap these days.
  10. dman_113

    dman_113 Beware the Jabberwock, my son!

    Nov 4, 2007
    THE DRIVES MUST DIE HAHAHAHA, but really kill'em I spent 4 days last year working for my friends uncle's computer company behind their office with a few boxes of hard drives and a pick ax. The way they looked at it was that the cost of the drives is nothing compared to the damage that could take place if confidential info was to get to the wrong people.
  11. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    Thanks for all the info. I'm not too keen on this new hard drive thing. It seems that I should just keep the computers in my closet. :)
  12. +1 to destroying the hard drive. It's really the only way your info is 100% unreadable.

    When you delete something off your HD it doesn't actually get deleted and only marked as usable or free space. Eventually as you download or create new files this deleted item will get overwritten. You can download free utilities that will overwrite free space on your HD many times over making it virtually unreadable except for those with the knowledge on how to recover it.

    If your selling it to someone you know, or to someone who doesn't have the know how to get your info after a wipe and reformat more than likely you will be okay. It's still a chance, but after a wipe and reformat the person has to know what to look for before he/she can piece it back together.

    In short. Doing a wipe and reformat you should be okay, but there is still a chance.
  13. Actually, if you know how to reload windows you already know more than enough to replace a HD yourself. If the OS is XP or newer it's really simple.

    Replacing the drive is pretty simple. One data cable. One power cable, and four screws to un-mount it. Put in the new drive and reverse your steps. Power it up, pop in the windows disc and reboot.

    If you want to go the extra mile, look up your computer specs and download the latest drivers.
  14. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Feb 19, 2004
    Ottawa, Canada
    Sell it without a drive? You won't get as much, but it won't be taking up room.
  15. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
  16. msquared


    Sep 19, 2004
    Kansas City
    This is only sort of true. When someone takes a disk that's had all of its bits flipped and restores data from it, they are able to do so because the magnets on the disk aren't exact enough to push the physical positioning of the bits to "true zero" or "true one". They get somewhere in the vicinity, which is close enough for the heads to store and get that data. It's not close enough for someone with the right forensics hardware to be fooled and reconstituting the data is easy at that point. It's sort of like with audio cassettes, how just recording stuff over already recorded stuff doesn't quite work. You have to record blank space over the top once or twice and then record your stuff.

    If you flip every bit on the disk to "1" and then back to "0" and back and forth several times, eventually the alignment of the bits will be such that even with an electron microscope you couldn't take the platters out and reconstitute the data. And at the point that someone is using that level of hardware to find out what's on your disk, the money is better spent elsewhere on different kinds of surveillance.

    Usually what is done though is to take the output stream of some random number generator and write the results to the disk several times. This makes the bits sit at 1 and 0 in random order rather than in an order which reflects where they sat previously. You do that on a disk a few times and, if your entropy pool is sufficiently large, it's impossible to reread the data using today's technology.

    Nino, a decent data wiper is DBaN:

    When I was working as a sysadmin at the US EPA, we had to physically destroy any disk we retired and document the destruction procedures we took. Some of those were really fun to write up. Many of the magnets on my kitchen fridge are from those old hard disks. :)
  17. MonetBass

    MonetBass ♪ Just listen ♫ Supporting Member

    Sep 15, 2006
  18. Yvon


    Nov 2, 2000
    Montreal, Canada
    you can format the hard drive. Fill it it with junk and format again.