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Summary: Erasing your hard drive before you give it away is important. Exactly how thorough an erase you need depends on your data and level of paranoia.
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I would like to clear off/erase all the programs on my hard drive and clean it up so that it's available for donation. What's the best/simplest way to do this? |
To begin with, good on you, not only for your donation but for thinking to do this. All too frequently we hear of computers donated by banks, hospitals, or other institutions turning up with all sorts of private information that should have been erased first.
The best way? Well ... how paranoid are you?
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Conventional wisdom is that reformatting your disk is the right thing to do. And I agree with that, if done properly.
What do I mean by "properly"?
Windows (all versions), and even MS-DOS before it, has the option to perform what's called a "quick format". In reality, a quick format does very little except create an empty root directory on the hard disk and possibly add a label. The rest of the disk is actually assumed to be properly formatted already and left alone. That's why it's quick.
And that's why it's insecure. Since the rest of the disk is left untouched, any data that may already have been there will remain. Many commonly available disk recovery tools will be able to recover data from a "quick" formatted disk.
So the basic and common answer is to reformat the disk, making sure to specify unconditional format. Depending on the version of Windows or MS-DOS you have, that's typically a FORMAT /U at the command line, or making sure that Perform a Quick Format is not checked when using disk management tools.
And that's my general recommendation.
But... here's where paranoia sets in.
It's theoretically possible to recover data even after a disk has been unconditionally formatted. It's not easy and may require special tools (both hardware and software). In general it's a very expensive process. But it may be possible.
It's a common recommendation to use a big heavy magnet to really erase a hard disk. My advice: forget it. Any magnets you're likely to have around the house, even your big speaker magnets, are unlikely to affect your hard disk in any significant way.
An alternate approach is to do that unconditional format several times. Not a bad idea, and if you can I'd also alternate file system types, allocation sizes, and whatever other parameters you have control over between successive formats. It's not bullet-proof, but it will make that difficult potential recovery even more difficult.
But to really, positively, and permanently destroy your data you need to physically destroy the disk. Personally, if I care enough to go this far I use a drill press and drill a few holes all the way through the hard drive casing, through the disk platters, and out the other side. (OK, ok ... even then it's possible for some data recovery by a seriously dedicated, and seriously well financed, expert ... but it's very much like taking a bucket of shredded documents and trying to put them back together - one heck of a lot of work.)
Unfortunately, that level of destruction also makes your gift significantly less useful.
I'd stick with reformatting.
Related:
How do I reformat my machine if I don't have a Windows CD? Reformatting a machine is a major step that erases everything. Unless you really know what you're doing, you're going to want that Windows Setup CD.
What should I back up before reformatting? Reformatting a machine is a major operation that starts by erasing everything. Having a good backup is critical to preserving your data.
Must I reformat if I replace my motherboard? Reinstalling Windows is often recommended when replacing a motherboard with a different model. But there are scenarios where it may not be needed.
Article C2247 - December 26, 2004
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Erasing your hard disk does NOT erase your BIOS.
Leo
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What about encrypting the data? then I would think it could (in many cases) become an impossible task to decrypt the data, from the partly recovered data you get from the drive.
Specifically I think if you used whole drive encryption from day one on the drive you might be ok.
But if you're suggesting to encrypt just prior to disposal, I'd just format instead. Or break out my drill press. :-)
-Leo
>Amanda Stephen:
>can I ask a question. I had a new hard drive with >new bios put in. If I erase the HD will the BIOS >be left so I can reinstall the OS.
The Bios isn't saved on the hard drive. It's normally saved on a chip on your motherboard. This chip can be overwritten or in some cases physically replaced. Without a bios a normal PC is useless, because is can't load an operating system and thereby can't be operated ;-)
Posted by: Simon at July 29, 2008 4:46 AMWhy erasing hard drive is required ?
Get your answer here...
http://www.eraseharddrivedata.com/wiping-hard-drive-process.php
Posted by: Erase hard drive data at August 1, 2008 12:00 AMTo erase the data on my old hard drives, I strip out the hard drive from the computer and then use a screwdriver to open the hard-drive case. I then light up my acetylene torch and cook the actual platter.
Within a few moments, it's melted and virtually destroyed. I can't believe for a second that any data is still there.
I also have a giant magnet that weighs about 20 pounds. I've often wondered what might happen if I put it in contact with the platter.
(BTW: Tim's a friend, and posts less destructive home-improvement tips over at Ask The Builder.)
10-Dec-2008
DBAN works well but has limits too.. here is a good versus article. DBAN Versus Wipedrive
Posted by: Kilroy at January 5, 2009 10:06 AMI have gone to c:\ and put in "format/u". It keeps telling me I have wrong or missing parameters... Please help I am trying to erase a hard drive so that I may give the computer to someone else. Thanks
19-Jan-2009
Does formatting the hard-drive during reinstallation of the operating system via the original CD (vista or XP) adequately erase the HD
06-Feb-2009
Hi! I have a failing external hard drive that I want to give to a local computer recycling center. I want to do this safely and I'm wondering if I can use a bulk eraser - the kind that radio stations used to use to erase reels of audio tape? Thanks.
17-Mar-2009
I would advise degaussing the drive. After all it is a magnetic storage device. Had a quick google read more here...
http://www.pureplanetrecycling.co.uk/data-destruction.htm
12-Jun-2009