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General discussion

3/15/04 Purge data before passing on your PC

Mar 10, 2004 5:16PM PST
Question:
I'm donating my old PC to charity. What should I do to make sure all of my information is completely gone?

Submitted by Jack K. of Jacksonville, FL


Answer:
There are basically 3 ways to eliminate information from a hard drive (sanitizing a hard drive):
1)Overwriting
2)Degaussing
3)Destruction

For the non-techie, the basic file deletion provided by the O/S does not actually remove the data from the hard drive. Data pointers and file locations are the only information deleted. There are several methods and software programs available that can "un-delete" these types of files. So the only really secure method is to completely remove the data from the hard drive.

1) Overwriting a hard drive is probably the solution that this particular user is interested in, since they wish someone to re-use the hard drive. There are several free, shareware, commercial products, and even services that can provide this option. The basic concept is that the entire hard drive is re-written with useless or random information over every track and sector. This is not absolutely reliable, as I understand there is now even methods that allow a forensic search of a hard drive allowing information that has been overwritten several times to still be recovered.

2)De-gaussing (de-magnetizing) is also a way to magnetically destroy data on hard drives. This takes a De-gaussing machine, which the general public does not usually have immediate access to. There are service companies that can perform this function for you, and are often used by commercial enterprises when they have multiple hard drives to purge. Unfortunately, degaussing can often render a hard drive unusable, if the demagnetizing affects the spindle motor or eliminates the timing tracks on the hard drive.

3)Destruction is fairly obvious. The hard drive is physically destroyed (smashing the platters or rendering them magnetically useless, which eliminates all data, but also eliminates the hard drive from any future use!. This can be psychologically gratifying to those who have a particular passion for ten-pound sledgehammers, and a latent hatred for all things technological.

The only absolutely safe method is physical destruction. If the user has ANY reservations about someone finding their data on a hard drive and considering the reasonably inexpensive replacement cost of a hard drive (under $100) I would recommend the sledgehammer option.

Happy Computing!

Submitted by Steve P of Toronto, CANADA

Thank you for the great submission, Steve!

Below I have also listed a few honorable mentions:

Answer:

The level of hard drive security for the purpose of recycling, donating or selling old PCs would greatly depend on the information that has been stored on that hard drive and the essence of the person disposing of said PC.

The act of cleaning information from ones hard drive can range from total destruction of the hard drive to just being sure that the recycle-bin has been properly empty.

There are a number of programs that will aid in removing personal information form your hard drive, which contain numerous files that most users know nothing about. In fact most users think the recycle-bin destroys their information, wrong. Some of these programs are; BC Wipe Software, Easer, Evidence Eliminator and Norton System Works.

If you want to be at least 99% sure everything is gone, use Autoclave. This free program boots from a floppy disk and overwrites all data on your hard drive, but its still possible that the FBI, CIA or NASA could use microscopes to find information.

If you want total piece of mind and are a hard-core security person, put in a new hard drive. Then destroy your old hard drive and all its information by using Autoclave, followed by degaussing and then destroy the drive with a hammer or other method of destruction. Finally, put the bits and pieces in separate bags and put each bag in difference trash containers around town, or transport to another state or country.

There is allot of good information on the Web, including an article at Tech TV, Dark Tip: Destroy All Data, or Information Week, Langa Letter:The "Dead Drive" Security Loophole. So the best tip is to become INFORMED. Learn what is stored on hard drives, where it is stored, how information is over-written, and why it is possible that your information may not be 100% destroyed using software programs, you'll be in for a shock.

Make it a great day,

Submitted by James W. of Pulaski, VA

***************************

Answer:

Anytime you need to clean a hard drive, the most economical and easiest answer is to use the utility provided by the manufacturer. If not already available, it can be downloaded from website. Most manufacturers offer utility and/or diagnostic software for their hard drive maintenance. Most will work with other manufacturers products, some will work only if one of their drives is attached. The zero write function should be used to write zeros to the entire hard disk. You can choose how many times to loop thru the process. If you are in business and need DOD security, you should know enough and have enough funds to pay for a commercial grade product.

Maxtor: http://www.maxtor.com/en/support/downloads/powermax.htm
Western Digital: DLG Tools: http://support.wdc.com/download/index.asp#dlgtools
+ other manufacuters

Most common users don't need DOD level wipe but if by some chance you think you do, try these freeware products. All are excellent products.

AnalogX SuperShredder: http://www.analogx.com/contents/download/system/shred.htm
Active KillDisk: http://www.killdisk.com/eraser.htm
DataDestroyer: http://tomorroware.blix.com/DataDestroyer/
PC Inspector: http://www.pcinspector.de/emaxx/uk/welcome.htm
Wipeout: http://www.securitysoftware.cc/apps.html

There are tons of other programs, freeware and commercial, that are available.

Submitted by Cheryl T

***************************

The safest solution would be to low-level format the hard drive, writing and
re-writing characters to every sector of the disk. This has the dual effect
of making your information almost impossible (difficult even for
sophisticated equipment) to retrieve. Often, hard drive manufacturers
include software specifically designed for their drives that will allow you
do to this.

If that's not possible, the next best thing is to perform a traditional
format and re-install of your operating system. This will ensure that any
old settings or files with personal information have been purged.

If THAT's not possible because you do not have any installation media, you
can manually remove personal settings from applications (e.g. e-mail
settings from Outlook), then manually clean up any rogue registry entries or
files with personal settings. Note that your "name and company" information
may still be in the "System" control panel (among other places) unless
manually removed.

I would strongly suggest one of the first two options if it's possible.

Submitted by Mike H. of Salt Lake CIty, UTah

***************************

1. fdisk should do in most cases: delete any partition and create new ones. Format again. There are many forensic tools that can retreive info. But not the vast mayority of users. Installing again OS and software makes it harder to retrieve info, specially if you use a diferent file system, ie change fat for ntfs or ext2 for example.

2.There is a simple script on Debug wich clears your hdd (in some place of my Cd collection, also on the internet). Partition and format. Only sophisticated forensic tools can retreive some info.

3.Almost all hdd manufacturers has zeroing tools and low level format tools. Drawback: you should know your hdd brand and model as these tools are tailored to brand and model family. Again only very, but very sophisticated forensic tools can retrieve some info from your hdd.

4.If you are paranoic, there are many good software tools on the internet (free and/or shareware) that write zeros, then ones, then zeros again or reverse your hdd magnetization as many times you wish. Hard to say if some tool can retrieve any info.

5.Last resort: buy a new or a refurbished hdd and break yours with a hammer and then burn it with a torch. Shure no one can retrieve any info.

Submitted by Eng. B

Discussion is locked

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 12:12PM PST

As a data recovery engineer I can tell you some people are correct. There are programs that will overwrite everything and complete physical destruction is very effective. However, reinstalling your operating system after a reformat is not highly effective. My company gets numerous jobs that have this done to them and we get a large amount of information back.

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Re:Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 11:29PM PST

Is that true of low-level formatting as well as of reformatting a logical or physical drive without departitioning?

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 10:07PM PST

I`ve tried to re-format this Win XP PC, but I get a message in dos from my old win 98 boot disc, I don`t have one ( a boot disc) for this PC,that this(computer) has an "ntfs" drive, and it won`t let me do it. I don`t want to let it go unless it`s formatted. Is there a way to do that? joe

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Re:Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 11:34PM PST

Sounds as if you have a NTFS (for NT file system) partition, so you can try fdisk to eliminate the partition(s) and then low-level format and reinstall.

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 10:23PM PST

The best possible thing to do is to replace the hard disk by a new one or a used one from another source whose data aren't of any interest.
Thus you can keep your old one to install it as second disk or whatever you want, and be sure that your data are 100% safe.

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Re:Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 11:36PM PST

This obviously written by a great thinker!

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 14, 2004 11:25PM PST

Physical destruction of the HDD is unnecessary, unless the DATA must be DESTROYED. If you are willing to pull the drive out of the PC (with or without installing a new or used replacement for the next user), then you can just install your old drive into your new PC, barring any incompatibility issues, or lock it away for safekeeping.

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 15, 2004 12:44AM PST

There is is program called "Delpart", which is used to delete NTFS Drives and other Hard Drives with sensitive information. Once you use it nothing can be recovered. See if you can find it, if you do not beleve a standard format is safe.

Just remember, once you delete the drives, the information is gone forever.

Good Luck,

jrburns
Los Angeles, CA

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 16, 2004 4:18AM PST

I have a somewhat similar problem. I have a machine with some files I need to delete before turning it over. When I try to delete them through windows explorer, the files come up 'access denied', stating that the file may be in use. This happens with quite a few files, which have apparently been left in an un-closed state.

The machine is a WinXP Pro box. I'd love to try booting to a floppy, but it's a laptop with no floppy; I have neither a USB floppy nor a CD-ROM replacement floppy to install. Is there anything out there that might be able to address these stubborn files?

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Re:March 8, 2004 Membership Q&A Newsletter
Mar 17, 2004 12:11PM PST