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  #51  
Old 02-13-2019, 11:37 AM
Tatterdemalion Tatterdemalion is offline
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Quote:
Originally Posted by DPRK View Post
How is it done, and what types of magnetic discs / flash memory are vulnerable?
I was going from memory, but a quick search turned up this reference: http://www.nber.org/sys-admin/overwr...a-guttman.html

I guess the danger is more theoretical than real, but it seems to be at least theoretically possible to recover data even if you have overwritten it.
  #52  
Old 02-13-2019, 01:29 PM
typoink typoink is offline
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Quote:
Originally Posted by Tatterdemalion View Post
Unfortunately no. All that does is erase the index to the data.
To expand slightly if this isn't clear: when you delete files from a hard drive or format it, the computer doesn't actually "delete" the data (because it would both be slow to do so and would probably shorten the lifespan of drives dramatically). Your drive has a table of contents where it stores info like, "picture.jpg is stored in location 15340 - 15420." When you delete it, all the hard drive does is delete that pointer, so it now doesn't think picture.jpg exists and thinks locations 15340-15420 are free to use. However, the data for picture.jpg is actually still there, and software exists that can find and reassemble it very easily. When you format a drive, all you're doing is deleting the WHOLE list of pointers; all the data still sits exactly where it was.

To prevent that, you need to overwrite the data on the drive. Apps like DBAN will basically overwrite ever location on the drive with random 1s and 0s to make the original file data impossible to access.
  #53  
Old 02-13-2019, 02:02 PM
SigMan SigMan is offline
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This brings up an interesting question about format. We have two methods, quick format and full format.

What are the difference?
  #54  
Old 02-13-2019, 02:03 PM
Tim@T-Bonham.net Tim@T-Bonham.net is offline
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Why discard it? Donate it for re-use!

Quote:
Originally Posted by Hari Seldon View Post
I am about to take on old Win-XP computer (yes it is that old) to a recycling centre. The computer still runs and of course contains a lot of personal stuff on it as well as old passwords. For example it automatically connected to my home Wi-Fi. What should I do to wipe the disk?
Why are you discarding a working computer? Donate it to one of the many charitable organizations that refurbish old computers and make them available to poor people. They have experts who regularly clean machines, erase data, and reset the operating system. (With a machine this old, they will probably install a Linux OS & applications. So even more likely to completely obscure whatever data is there now.)

Remember, it's Reduce, then Reuse, and only after that Recycle.
  #55  
Old 02-13-2019, 04:12 PM
AHarris AHarris is offline
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Quote:
Originally Posted by SigMan View Post
This brings up an interesting question about format. We have two methods, quick format and full format.

What are the difference?
A quick format recreates the file structure.

A full format takes longer because it checks the drive for bad sectors before recreating the file structure.

In both cases the new file structure is empty. However, someone with the appropriate tools can recover the data pretty easily.
  #56  
Old 02-13-2019, 04:52 PM
Hari Seldon Hari Seldon is offline
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Here is my experience. I got the dban and also a program called universal usb installer and installed it on a usb. When I tried to boot my old computer from the usb, it turned out that was not on the boot list. The old computer did have a CD reader and booting from a CD/DVD was an option. So I put the dban on a memory stick and clicked on the .iso file and, lo and behold, it offered to burn a CD. I had some blank CDs and no further use for them so I put one in and burned it. I also set the boot sequence to CD/DVD and tried to boot from it. I know CDs take a long time to boot, but a half hour later all I had was a black screen.

It is a laptop and I don't have a tool to open it. Maybe a table saw if I had one. I'm to that point now. And my wife wants it our of the house (we are preparing to move).
  #57  
Old 02-13-2019, 06:56 PM
Hari Seldon Hari Seldon is offline
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Finally, I discovered that a very tiny phillips screw driver will unscrew the screws on the underside and I was lucky to be able to find the compartment that held the disk on my second try and have taken it out. I will take the computer to the recycling place and the hard drive to my office and ask the sysop to do what she will with it.

I would have been perfectly happy to donate it to charity. But it wasn't working very well (wouldn't download stuff from the inet, although it connected immediately to my home network--one of the reasons I want the disk wiped.
  #58  
Old 02-14-2019, 08:48 AM
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ftg ftg is offline
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Quote:
Originally Posted by Hari Seldon View Post
I would have been perfectly happy to donate it to charity. But it wasn't working very well (wouldn't download stuff from the inet, although it connected immediately to my home network--one of the reasons I want the disk wiped.
Sounds more like a software rather than hardware problem. A disk wipe, OS reinstall would likely have resulted in a reasonably working computer with no hazards to you.
  #59  
Old 02-14-2019, 12:36 PM
typoink typoink is offline
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Quote:
Originally Posted by Tim@T-Bonham.net View Post
Why are you discarding a working computer? Donate it to one of the many charitable organizations that refurbish old computers and make them available to poor people. They have experts who regularly clean machines, erase data, and reset the operating system. (With a machine this old, they will probably install a Linux OS & applications. So even more likely to completely obscure whatever data is there now.)
I agree that donating is always best, but I'll also say that donation facilities may actually not even accept a machine this old. Worth asking, but a lot of them don't really want older desktops. There's not enough demand, and much newer desktops are cheap and plentiful enough to fulfill demand. XP-era systems are likely to just go straight to recycling, maybe after having the wires stripped.

Also, I would still recommend wiping your harddrives before donating a system. In my experience, wiping the hard drive data is NOT done when machines are received, only when the drive is eventually reused. This means that, if your system is parted out (and most are), that drive will be sitting on a shelf where any of the young, bored volunteers could grab it and use a usb adapter to check out the drive contents. Or somebody could buy the drive off the shelf (since these centers usually sell parts to the community) and walk out the door with your personal data intact. Not a SUPER high risk, but easy to avoid. Pretty sure the center I volunteered for actively encouraged people to wipe their drives before donating.
  #60  
Old 02-14-2019, 01:15 PM
SigMan SigMan is offline
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I got my Amazon Fire 8" Tablet for $50. Old computers cannot compete with this. It is portable and self contained. You can use your phone link up or wifi for access to the internet.
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