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Damaged External Hard drive

Hi folks,

I have a damaged external hard drive (it fell) and i want to retrieve important data from it.

When i plug it in, it says something like "this hard drive must be formatted before you can use it"

Any ideas?


6 Solutions
Darius GhassemCommented:
You are most likely going to have to send it off to retrieve the data off the hard drive. If the HD is saying to format then all tables have been damaged.
IrishKenAuthor Commented:
I was thinking what if i formatted it then used some undelete type tool to recover the deleted data?
Darius GhassemCommented:
You are running the risk of damaging the data more by running a format on the HD. If you want to have the data then send it off don't mess with it anymore.
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You can use an undelete tool to recover the data (most likely).  But don't format it... you'll lose everything for sure.

Undelete tools (the one I use is GetDataBack - pricey, but works wonders) will find the hard drive and be able to scan the drive without it having proper "formatting".  Good tools will run through and essentially "rebuild" a FAT table in order to recover files from a damaged device.
Have you attempted to put it in the freezer? I was a tech for many years and occcassssionally this worked. Make sure the freezer isn't too moist. But sometimes freezing the HD will give it just enough life to get your important files off.
Freezing really only helps in cases where overheating has caused damage so there are thermal related problems.  The idea is, by super-cooling it, by the time it heats up and starts having thermal related problems you will have bought yourself enough time to get everything off as fast as you can.  A few hours tops.  You don't want it in there for a week, imagine starting a car engine in Winnipeg in the midlle of winter with no lubrication... you wouldn't want to do that.  Even then it needs to be dry no moisture and sealed in a bag when cooled, otherwise frost can form (which will be super-bad on the surface of the disk when the read-write heads try to hover along thanks to the Bernoulli effect; alternatively you can get condensation which is moisture which is a big no-no in electronics also.  'nuff said.


You've got the wrong idea thinking to format the drive so you can use an undelete, just try to use a recovery tool, you can try different ones since they use different algorithms, and different ones have different free trials http://www.pcinspector.de/file_recovery/UK/welcome.htm   http://www.piriform.com/recuva/download/standard  
http://www.stellarinfo.com/   http://www.runtime.org/  http://www.ontrack.com/

A program like EasyRecovery Pro 6.04 is just like what the data recovery labs use to piece together files they're trying to recover from a damaged disk.  It can be a bit tricky.

The key here is to NOT alter the "patient" drive, you attach it as an ancillary drive to a working system and you install the recovery tools on the working system, and then attach yet another drive if necessary to have the free space needed to recover files from to the patient onto.  As a rule the better tools do not "try" to modify the broken rive because what if they get it wrong, they'll further confound the problem.

Simple undelete tools try to undelete directly on the drive in question making alterations to it.  I don't think your situation calls for that kind of shallow approach.

Something else you need to consider, the impact of the fall could have caused damage to the transport or irrevecable damage to parts of the surface of the disk, creating bad sectors that are unrecoverable.  THAT is alot more serious than undeleting or the table of contents (FAT or MFT/inode tables) were accidentally overwritten.

If bychance the damaged area of the drive happens to only be the "table of contents" then maybe the data files themselves can be retrieved.  File recovery software relies on the fact that files are stored on the drive as a series of blocks into a file chain, each block has it's predecessor and successor, so if it can piece together all the predecessors and successors of a file chain in theory it can recover said file.

If we were talking about an accidentally erased partition and/or partition information and/or master file table accidental formatting THAT would be one thing...

BUT, by your own statement, this is LIKELY ACTUAL DAMAGE to the disk.

This is why the wisest of experts have simply said: you need to send it to a data recovery lab.  When you proffered the idea of formatting you pretty much tipped your hand that anything else is beyond your realm of experience or expertise.

If you push your luck you could very well push it over the edge.  If there are scrapings or shavings inside, and those get caught up against the read-write head, compared to the microscopic gap it normally floats over the surface those will seem BOULDER sized and could start scraping even more.  If you hear scraping or grinding noises, STOP immediately, cut power, go no further, STOP.

If/when the drive attempts to read data from bad sectors, you may hear click click or ca-chunk ca-chunk a little, that's not great but is a normal sign of bad blocks as the drive retries, returns the heads to sector zero and back again, verifying in case there is a drive alignment problem.  If it's excessive the drive may very well "spin down" and stop all further operations, depending how well and how smart the logic board firmware is.

It might help a little if you can remember if it was FAT or NTFS, but the tools should be able to figure that out.

Certainly formatting would further confound the problem.

It seems unlikely that you'll magically rebuild the lost formatting and this drive will be back to normal, but you can pray for a miracle.

You likely need not spend inordinate amounts of time trying to recover .dlls, .exes, programs and oeprating system, instead you may want to concentrate your efforts on recovering user DATA, photos, documents, email, music if any, or at least more or less a list of what documents and photos and music had been there if you can't actually retrieve it.

Remember the three first commandments: first do no harm, if it ain't broke don't fix it, do your backups.


having said all that, let's suppose for a moment that you DO have a fairly recent backup, or somewhat recent.  Well then my friend you have more wiggle room to experiment with this drive in the hopes of getting back a few days or weeks recent work.  Consult with the user extensively.  How crucial is the difference between what's on there and what on the backup?  Is a multi-million dollar contract at stake?  If so, a data recovery lab seems a no-brainer.

What a data recovery lab does, is you know those "clean rooms" they make chips in, the guys in the white space bunny suits, no dirt or dust whatsoever (remember the boulder analogy?), well what they do is they crack open the drive, they carefully inspect the drive platters surfaces for shavings and scratches, carefully removing them with vacuum air and cleaning, then they transfer the platters to a special piece of equipment, a sort of pseudo drive, and they program in the tracking, sectoring, blocking information, an then use the device to read as much data as possible off the damaged drive onto another drive of the same layout, and then THAT drive to try to piece together the files from since the original drive was too much at risk.  It's expensive work and equipment so it comes at some cost.

Often many data recovery labs will do a free assesment, but then if you choose to go ahead the cost is a bit higher; they have to pay for those free assessments somehow but really they're very good at their work so hope you'll usually opt to use the service.  Sometimes they have some room for negotiation, like say if you agree to go straight for the reovery and skip the assesment, the price quote might be slightly lower.

BUT, back to what I was saying, IF you have a backup.

Well first, you should already be in the midst of looking into the backup, seeing if it can be recovered to a different drive and verify what's there.

IF, IF you have room to mess with the drive, there's another aspect to consider.  SpinRite 6 is a program that tries to recover data off of bad blocks.  Where something like a chkdsk/r will scan for bad sectors, it only tries about a half-dozen times to read and recover the data before it gives up and "corrupts" the affected file by putting zeros in place of the lost data.  I never use /r (ditto the checkbox in scandisk to search for bad sectors, same thing).  That behaviour is only ok when formatting/reformatting a disk when you don't care if the data is recoverable you are starting over fresh and just want the bad sectors gone mapped out.  SpinRite on the other hand tries hundreds of times to read the data, uses complex mathematical algorithms to detect differences between the samples and piece together most of not all of the data from the bad blocks before "detouring" that part of the disk to a "spare" sector and making the bad sector bad not to be used.   Obviously for parts of the magnetic surface that are scratched off even SpinRite cannot get that information back.  You can get an idea by reading about it at http://spinrite.com 

SpinRite operates on the disk, it does make changes regarding bad tracking around the spots it has trouble with.  The danger, as explained, is if there are shavings then it too could make things a little worse with further sratching.  Just simple reading can do that, nevermind writing or trying to re-read hundreds of times.

A tick tick, click clik, chunk chunk noise realign tries when dealing with bad spots is one thing, a screetch screetch, grind groan, metal on metal sounds are quite another, you'd best STOP if that's happening.

Just in case it's best to orient the drive vertically not horizontally, and give it a couple of tap tap taps while it is off to try to send any shavings out to the side and out of play.

Most drives have S.M.A.R.T. technology, that monitors things like how many of the "spare" sectors have been used up for bad sectoring and if  it's almost all used up that would raise a red flag.  If many bad sectors happen all-in-a-row that too would raise a red flag as potential serious damage since bad sectors are a normal thing now and then but not in epidemic rate.  Also if the drive has trouble spinning-up, mainting speed, if the alignment needs to be often retried, all can raise a flag.  With it turned on in the BIOS, each time the computer is turned on and does it's power-on self-test (POST) if the SMART flag is red, it would stop and warn the disk is about to fail.  SpinRite looks at SMART.  While running Windows you can check the SMART of a drive with this free tool http://www.beyondlogic.org/solutions/smart/smart.htm

So, you may be quite lucky and whatever damaged the formatting may be able to be undone somewhat easily, or the damage may be more difficult.

Whatever course you should decide, best of luck.
P.S. Have you tried connecting it to a couple of different machines?  I only add this because sometimes Vista/Win7 can be quite sensitive/picky about the condition of a filesystem, whereas WinXP is not as thorough and will sometimes show the drive letters and you will only encounter problems when you hit a bad spot.  Some external drive enclosures are good at handling bad spots, failed to read file X and move on, whereas some are lowsy and freeze or reboot sending you back to square one.  Ditto the logic board firmware on the drives themselves: enterprise class drives often have ECC and extensive bad sector handling built-in whereas consumer-level drives not so much.
You might try removing the drive from the enclosure, inside it is likely a standard drive either SATA or IDE (PATA) and could be connected as ancllary drive directly inside a desktop PC (master on the secondary 2, 3, 4, or as slave).  This will also be much FASTER operations than if it has to pass through the much slower USB, and in some cases the USB prevents some tools from gaining the kind of direct access to the drive that it needs.
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