Clean a PC before selling?

[Plato]

can often recover even overwritten data. For that reason, the US
government destroys drives containing sensitive data in a furnace,
rather than relying on overwriting.

Or even better, put the drive in the toilet in a redneck's trailer for a
week.

 

[PD]

You really don't understand the issue.  In essence what you are saying
is that you would have no qualms disposing of a file cabinet full of
personal/financial papers by simply putting it at the curb for garbage
pickup or giving it to a thrift shop.  The simple formating solution
that you offer is akin to using whiteout liquid paper to cover the
folder names but otherwise leaving everything in the file cabinet, as if
people won't be able to look in the file folders because they have no
name or identification written on the tabs.  For your own sake you
better reconsider your advice when comes time to dispose of your own
computer!

http://zapatopi.net/afdb/

 

[John John]

http://zapatopi.net/afdb/

Excuse me Sir, but you are a fool! You have absolutely no understanding
of data protection and basic security concepts. No one in their right
mind would follow any of the advice that you have given on the issue.
If you cannot understand the simple concepts explained in this thread
then your computer skills leave much to be desired. Any five year old
child would be a better computer technician than you, at least a five
year old child is willing to learn, you on the other hand must have
cement in your cranial cavity!

John

 

[Charlie Tame]

<snipped some conversation for brevity>
Suggested highly that the entire conversation be reviewed for complete
comprehension, and luckily Google does archive it nicely for us:
http://groups.google.com/group/micr...5/71ecb5f091536425?lnk=st&q=#71ecb5f091536425

I read somewhere that as a drive wears the head to track alignment "Can"
slip far enough that later erasure does not always complete the job and
so with a program that can (say) half step the heads recovery of some
data may be possible.

Also with NTFS there's the somewhat mysterious issue of Alternate File
Streams.

Given the number of completely worthless "Security" programs out there
how does one really tell if a drive has been "Securely" wiped.

So I think much of what has been said here is accurate as far as it
goes, but I also think it is impossible to completely rule anything out.

I reckon superglueing broken platters together is probably as close to
impossible as it's going to get so I will stick with the 4 pound hammer

 

[Bob I]

Current drives are self-calibrating, so as maintain head alignment. You
may be remembering the old servo drives and some were so bad that you
had to LL format them in the orientation they would be used, or you
would corrupt everything.

 

[John John]

I read somewhere that as a drive wears the head to track alignment
"Can" slip far enough that later erasure does not always complete the
job and so with a program that can (say) half step the heads
recovery of some data may be possible.

That was the theory on old drives, on new drives that never really was
an issue. On the old class of drives it was thought to be an issue, and
what you say was thought to be possible, but not with any software
methods, it was thought to be possible with the use of sophisticated
laboratory equipment. That is why the practice of multiple wipes (as
many as 35 wipes!) was advocated and widely used, but even on these old
drives no one was ever capable of recovering data on a properly wiped
hard drive. However, with wobbly floppy diskettes some have actually
proven the technique that you describe.

Also with NTFS there's the somewhat mysterious issue of Alternate
File Streams.

That is a non-issue, on a securely wiped drive there is nothing at all
left on it, the alternate data streams are zero written along with the
files.

Given the number of completely worthless "Security" programs out
there how does one really tell if a drive has been "Securely" wiped.

So I think much of what has been said here is accurate as far as it
goes, but I also think it is impossible to completely rule anything
out.

I reckon superglueing broken platters together is probably as close
to impossible as it's going to get so I will stick with the 4 pound
hammer

The irony of the "sledge hammer" method is that by using the very
sophisticated microscopy methods that that the sledge hammer proponents
claim are "supposed" to "possibly" uncover files on securely wiped
drives it is possible to recover data on pieces of hard drives that are
as little as 1/125 of an inch in size! It would be a daunting task of
astronomical proportion and no one would care to do this on a drive just
for a fishing expedition, but if there was really important information
or evidence known to be on the drive it could be recovered if someone
wanted to pay. That particular scenario is a proven one, recovering
data on broken or bent platers has been done, but it isn't something
that would be done unless there was a real big fish to be caught! For
all practical purposes recovering data on a drive with bent or broken
platters is deemed to be nearly impossible, it would cost a king's
ransom but it is not beyond the means of exotic data recovery to recover
data on bent or broken platters, a properly wiped drive on the other
hand is beyond these exotic data recovery techniques.

If you are paranoid to that point then, yes, the only 100% absolutely
sure method is to do like Ken says and melt the drive! The deal is that
as far as securely wiped drives go no one has ever recovered data on
them. The risk is that the actual wipe might fail because of sloppy
users not using the right software or wipe method or because of
mechanical drive failure. In the case of mechanical failure the wiping
software cannot wipe all the sectors on the drive, however using the SE
commands secure erase software will or should alert the users that
mechanical problems prevent 100% secure erasure. Secure erase
overwrites all the sectors on a drive, including those that have been
marked as damaged or unusable and made unavailable to operating systems.
In fact for the extremely paranoid secure erasure is safer than the
sledge hammer! So your only other alternative is to go to a steel plant
or foundry and pitch the drive in the melting pot! Of course you have
to go to the steel plant and pitch it in the pot yourself, if you are
that concerned that data will be recovered on the drive you will not
trust anyone else with the task.

http://searchsecurity.techtarget.com/expert/KnowledgebaseAnswer/0,289625,sid14_gci1273281,00.html
http://cmrr.ucsd.edu/people/Hughes/CmrrSecureEraseProtocols.pdf
http://cmrr.ucsd.edu/people/Hughes/DataSanitizationTutorial.pdf
http://search.yahoo.com/search?ei=UTF-8&fr=yfp-t-501&cop=mss&p=verify+secure+erasure&x=0&y=0

http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml

John

 

[Jupiter Jones [MVP]]

"how "expert" is the recipient likely to be on a scale of 1 to 10"
And how about others directly or indirectly connected to the
recipient.
Another group you have conveniently ignored and yet they may have full
access to any and all data.

"are giving their computer to an ordinary person who is
clueless"Please prove this applies in this specific case.
Instead of stopping there as you have, look beyond.
There is potential risk there as well.

It is clear the OP will not achieve the desired result without
formatting and a little more.
However with your remarks it is clear you have more specific details
on the needs of the OP.
Please share that information.
Otherwise it seems your answers do not look out for other reasonable
possibilities.
Please refrain from posting the irrelevant link you have used before
as an answer.
It will only demonstrate you lack the specific knowledge to give a
reasoned answer.

Your insults scattered among your posts also demonstrate your own
insecurity with your views, otherwise you not have need to insult to
prop up your position.

--
Jupiter Jones [MVP]
http://www3.telus.net/dandemar

You can't. Even with a format, data recovery software can retrieve
files. The only way to make sure there is nothing left of your
activity
is to wipe the hard drive (Darik's Boot and Nuke is free; Acronis
Disk
Cleanser is good but not free) or smash it with a sledge hammer.

Fer crissake, m'man... the guy doesn't have to worry that the CIA is
gonna get ahold of his computer and scour it for details!

Folks who ask these kinda questions are giving their computer to an
ordinary person who is clueless - not to add, probably disinterested -
when it comes to things like that.

 

[Saucy]

Plasma furnace.