# Magnet used in cleaning a Hard Drive **URL:** \ **Category:** Factual Questions\ **Created:** [May 25, 2006, 3:15pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172 "2006-05-25T15:15:03Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Aceospades](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Aceospades](https://boards.straightdope.com/u/Aceospades)\ **Post date:** [May 25, 2006, 3:15pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/1 "2006-05-25T15:15:03Z")
I’ve heard many times that if I want to be really sure to get rid of any data on a hard drive, I have to rub a magnet over it a few times. Does this actually work? Would it damage my hard drive at all? My friend gave me his hard drive from his laptop (he upgraded) and I want to make sure it’s good and clean before I plug it into mine. ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [May 25, 2006, 3:21pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/2 "2006-05-25T15:21:35Z")
To make sure that it’s clean to use on your computer, all you need to do is format it. The people who talk about using magnets to completely erase the disk are the ones concerned about the NSA or the CIA using their arsenal of computer snoopery to find what was in previously erased/deleted files. And even then, there are software tools that can eradicate the contents of a disk more thoroughly than rubbing it with a magnet. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [May 25, 2006, 3:23pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/3 "2006-05-25T15:23:00Z")
> [@Aceospades](#): > > I’ve heard many times that if I want to be really sure to get rid of any data on a hard drive, I have to rub a magnet over it a few times. Does this actually work? Would it damage my hard drive at all? My friend gave me his hard drive from his laptop (he upgraded) and I want to make sure it’s good and clean before I plug it into mine. Do not rub a magnet on your hard drive and disregard any of the joke posts directing you to parody websites about cleaning hard drives with soap, sandpaper, very cold temperatures, etc. For your purposes it would be quite sufficient to delete the partitions on the disk and create a new one. Your OS installation procedure will most likely have a step that would let you do this (this assumes you’ll be reinstalling the OS, which of course you will, if you really want the machine clean). ---
**Author:** ![fubbleskag](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@fubbleskag](https://boards.straightdope.com/u/fubbleskag)\ **Post date:** [May 25, 2006, 3:26pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/4 "2006-05-25T15:26:49Z")
chances are you don’t have a magnet around your house large enough to affect the drive, and even if you did it’s not a reliable method. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 25, 2006, 3:33pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/5 "2006-05-25T15:33:16Z")
> [@Aceospades](#): > > I’ve heard many times that if I want to be really sure to get rid of any data on a hard drive, I have to rub a magnet over it a few times. Does this actually work? Would it damage my hard drive at all? My friend gave me his hard drive from his laptop (he upgraded) and I want to make sure it’s good and clean before I plug it into mine. I think you’re possibly confusing a hard drive and a floppy disk. Household magnets in close proximity can damage/erase a floppy disk but will usually have no effect on a hard drive unless the magnet is enormously powerful. Just re-partition and re-format the drive. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 25, 2006, 3:35pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/6 "2006-05-25T15:35:02Z")
A magnet strong enough to erase data from the platters will turn your hard drive into a paper weight. As I was reminded in a previous thread, modern hard drive platters contain embedded information called servo data, which the heads need in order to align themselves with the tracks. It is not possible to restore this data–it’s written in at the manufacturer using special equipment. Since you seem to be more concerned about simply being able to do a clean install with no conflicts with existing data on the drive, a simple format willb e sufficient. ---
**Author:** ![daffyduck](https://avatars.discourse-cdn.com/v4/letter/d/ec9cab/32.png) [@daffyduck](https://boards.straightdope.com/u/daffyduck)\ **Post date:** [May 25, 2006, 3:52pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/7 "2006-05-25T15:52:56Z")
_…Household magnets in close proximity can damage/erase a floppy disk…_ As a test, I once pinned a floppy (completely full with video) to my fridge with a magnet for a month and the disk read perfectly when I tested it. As always, YMMV, but I am very skeptical about any claims of data loss and “household” magnets. ---
**Author:** ![VenusProbe](https://avatars.discourse-cdn.com/v4/letter/v/e495f1/32.png) [@VenusProbe](https://boards.straightdope.com/u/VenusProbe)\ **Post date:** [May 25, 2006, 3:59pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/8 "2006-05-25T15:59:54Z")
Formatting should be enough. But when I really want to remove all traces of information from a drive I use [DBAN](http://dban.sourceforge.net/). It’s free and effective. ---
**Author:** ![Excalibre](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Excalibre](https://boards.straightdope.com/u/Excalibre)\ **Post date:** [May 25, 2006, 7:54pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/9 "2006-05-25T19:54:49Z")
> [@Q.E.D.](#): > > A magnet strong enough to erase data from the platters will turn your hard drive into a paper weight. As I was reminded in a previous thread, modern hard drive platters contain embedded information called servo data, which the heads need in order to align themselves with the tracks. It is not possible to restore this data–it’s written in at the manufacturer using special equipment. Since you seem to be more concerned about simply being able to do a clean install with no conflicts with existing data on the drive, a simple format willb e sufficient. Yeah, I wanted to emphasize this. If you actually manage to erase a hard drive completely with a magnet - which is probably fairly unlikely - it won’t work afterwards. To erase the data, a format is sufficient. If you’re worried about someone stealing credit card numbers or something, you can take stronger steps, but since it’s you using the hard drive, you can be fairly sure of what’s going to happen to the data on it. ---
**Author:** ![UncleBeer](https://avatars.discourse-cdn.com/v4/letter/u/977dab/32.png) [@UncleBeer](https://boards.straightdope.com/u/UncleBeer)\ **Post date:** [May 25, 2006, 8:01pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/10 "2006-05-25T20:01:00Z")
Well, what about an [eel skin wallet](http://www.straightdope.com/classics/a3_388.html)? ---
**Author:** ![Jake](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@Jake](https://boards.straightdope.com/u/Jake)\ **Post date:** [May 25, 2006, 8:14pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/11 "2006-05-25T20:14:14Z")
> [@UncleBeer](#): > > Well, what about an [eel skin wallet](http://www.straightdope.com/classics/a3_388.html)? I think Mythbusters kinda shot that one down. On erasures of the data on the stripe. Sorry, I can’t remember what episode. ---
**Author:** ![Aceospades](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Aceospades](https://boards.straightdope.com/u/Aceospades)\ **Post date:** [May 26, 2006, 1:17am UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/12 "2006-05-26T01:17:50Z")
My mane concern is hidden programs on the hard drive. I plan on installing a new full version of XP on to it. So I start up the laptop and insert the new XP CD. Reboot so that it boots from the CD. Go through the whole process. Does this guarantee that I have nothing to worry about? ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [May 26, 2006, 1:25am UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/13 "2006-05-26T01:25:52Z")
When doing your install you must make sure that you format the drive. You should get the opertunity to do so during the instalation process. Ensure that you do go through the path of repairing or upgrading. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [May 26, 2006, 2:00am UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/14 "2006-05-26T02:00:42Z")
> [@Aceospades](#): > > I’ve heard many times that if I want to be really sure to get rid of any data on a hard drive, I have to rub a magnet over it a few times. Does this actually work? Would it damage my hard drive at all? My friend gave me his hard drive from his laptop (he upgraded) and I want to make sure it’s good and clean before I plug it into mine. IF you have a really hefty (Powerwise) magnet coil and insert the hard drive into the center of the coik you can kiss it goodbye for future use. To be sure all the data is destroyed, disassemble the HD, remove the hard aluminum disks and cut them up or bend and pound them folded flat. NO one can recover the data. For any other reuse, simply reformat or use a disk manager that will overwerite the disc with 1’s and 0’s, then 0’s and 1’s, and repeat a number of times. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 26, 2006, 2:07am UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/15 "2006-05-26T02:07:19Z")
> [@daffyduck](#): > > _…Household magnets in close proximity can damage/erase a floppy disk…_ > > As a test, I once pinned a floppy (completely full with video) to my fridge with a magnet for a month and the disk read perfectly when I tested it. As always, YMMV, but I am very skeptical about any claims of data loss and “household” magnets. "Household and utlility magnets vary enormously in power, and “fridge clip” type magnets are typically among the weakest available. You can easily damage a floppy with some of the stronger magnets. ---
**Author:** ![fubbleskag](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@fubbleskag](https://boards.straightdope.com/u/fubbleskag)\ **Post date:** [May 26, 2006, 2:10am UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/16 "2006-05-26T02:10:52Z")
> [@gazpacho](#): > > When doing your install you must make sure that you format the drive. You should get the opertunity to do so during the instalation process. Ensure that you do **not** go through the path of repairing or upgrading. just to clarify this typo for **gazpacho** … during the install you will be prompted with a brief list of the partitions available to choose which to install Windows to; you can press ‘D’ on each of them to delete the partition completely, and then ‘C’ to create a new one - this will then force you to format at the very least the chosen install partition (the others can be formatted inside windows quickly & easily) ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 26, 2006, 4:29pm UTC](https://boards.straightdope.com/t/magnet-used-in-cleaning-a-hard-drive/358172/17 "2006-05-26T16:29:46Z")
> [@spingears](#): > > …remove the hard aluminum disks… These days, fewer and fewer drive platters are made from aluminum. Most platters these days are made of either glass or ceramic composite. Take 'em out and whack 'em with a hammer for 100% secure data destruction. And wear safety goggles, kids.