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Windows 7: 3TB Hard disc became "unallocated", how to recover?

12 May 2014   #1

Windows 7 Ultimate
3TB Hard disc became "unallocated", how to recover?

Hello! I recently bought a 3TB external USB hard disk, which suddenly did not want to start. When switching on, I could here the disk try to start to rotate, but it didn't, as if the provided power was too weak or so.

I unscrewed the disk from its housing and put the housing with its S-ATA-to-USB controller aside and plugged the disk - a "ST3000DM001-1CH166, Seagate Barracuda" - to a PC cases S-ATA Port, now it really started. Then, as soon as I started the disk manager, I was asked to "activate" the disk, which I did (maybe this was a fault?)

Now I have activated the disk, but in disk manager there are two partitions showing up now:
  • 2048 GB unallocated,
  • 746,54 GB unallocated

I installed EaseUS Data recovery wizard (to my systems hard disk of course) and started a recovery search, which took about 48 hours. I got a complete list of all files that where/are on the disk and obviously I can recover all, actually I started the recovery to another disk. But the complete folder structure would be lost, if recovering the files this way, all would be saved in one huge folder "NTFS lost files", or so. This makes this kind of recovery 99% useless for me.

Now EaseUS is able to save a once done search result and load it later, so one only once has to run that time consuming search. So I saved the result and interrupted the even much more time consuming recovery.

At least I know now that the files are all on the disk, and also is the folder structure, as I was able to see it in EaseUS too.

Now here is my question:

1.: Is there any way to recover the former "3TB-one-partition-state" without destroying the data on the disk? And 2.: Just for my understanding: Why do I see two partitions now? Is Windows 7 unable to deal with 3TB partitions at all?

This is my setup: Normal home desktop (self built) with 8GB RAM, Quad-Core @2,4 Ghz, no Raid or special stuff, Windows 7 Ultimate.

Thank you very, very much for your help, I really appreciate it!

My System SpecsSystem Spec

12 May 2014   #2

Microsoft Community Contributor Award Recipient

Windows 7 SP1, Home Premium, 64-bit

Wait for more comments, but I think your better move would have been to attempt to recover the original partition, rather than immediately try to recover the files.

If that disk originally had a single 3 TB partition, it was initialized as "GPT", not the more commonly found MBR. MBR partitions are limited to 2.2 TB.

That EaseUS tool you have may or may not have partition recovery capability. The standard recommendation on this forum for partition recovery is to use Partition Wizard:

Free download Magic Partition Manager Software, partition magic alternative, free partition magic, partition magic Windows 7 and server partition software - Partition Wizard Online

You might download that tool, but I'd wait for more comments before using it or EaseUS.
My System SpecsSystem Spec
12 May 2014   #3

Windows 7 Home Premium 32 bit

Yes, ignatzatsonic is right.

Run Partition Recovery Wizard in Partition Wizard Home Edition 8.1.1 ( As a matter of fact, you could have done that even without taking it out of the enclosure. Anyway ....)

Please follow the steps as shown in my post #3 in this thread. disk 1 is unknown, not initialized, unallocated

When after the quick scan the screen shows all your partitions, post a screenshot of the same and do not proceed without further instructions from this end. ( Do not worry and do things yourself if such instructions do not come immediately. It will all depend when I log on next and see your screenshot. If need be you can close Partition Wizard (cancel) and rerun it after you get instructions.Cancelling will not alter anything.)

When you initialised it you perhaps initialised it as an MBR disk which can only see 2TB. That is why the remaining space is shown unallocated.

We have to see the partitions shown and choose the right ones to restore the GPT structure.
My System SpecsSystem Spec

12 May 2014   #4

Microsoft Community Contributor Award Recipient

Windows 7 SP1, Home Premium, 64-bit


I just spent at least an hour reading through that link you provided above.

Can you clarify a couple of points:

Regarding Partition Wizard usage for partition recovery: When is "full scan" recommended? I notice in that thread that you recommended "quick scan". It showed "bad disk" and the thread then veered toward data recovery rather than partition recovery, with no attempt at "full scan".

For data recovery per se, is PhotoRec still the best free alternative and are its results as good as the $79 Ontrack EasyRecovery Professional? Or MiniTool Power Data Recovery?
My System SpecsSystem Spec
12 May 2014   #5

Windows 7 Home Premium 32 bit

I referred to only my post in that thread on how to use Partition Wizard which the OP can use. The rest of the thread and what happened is specific to that thread which is of no consequence to the OP here. The OP here need not look into any other posts in that thread.( I hardly remember any of it now )

OK, regarding the Quick Scan and Full Scan the general recommendation is that if a Quick Scan fails to show the partitions, run a Full Scan. One is a Fast Sweep and the other is a sector by sector read to ascertain the beginning of a partition if a fast Sweep somehow fails to identify the beginning of the partition. So far I have not come across a case where a Quick Scan failed that would have necessitated a Full Scan.

If Partiton Wizard shows a disk as Bad Disk even a Quick Scan will not run. May be that is the reason why I cut it and recommended Data Recovery after seeing that PW shows the disk as Bad Disk.

From all the user reports I have seen here, I have come to the conclusion that if PW shows a disk as Bad Disk no data recovery also works.

I would still recommend a Data Recovery procedure after pointing out the above, just to complete the process to satisfy oneself that he has done everything that he could possibly do.

I have no brush with OnTrack paid version of the Data Recovery Software and so cannot comment on it. PhotoRec is free and has recovered data even where other paid software has failed.

Stiverrom will vouch for it.

Best recovery software? (Windows 7)
My System SpecsSystem Spec
12 May 2014   #6

Microsoft Community Contributor Award Recipient

Windows 7 SP1, Home Premium, 64-bit

OK; thanks for additional detail.
My System SpecsSystem Spec
14 May 2014   #7

Windows 7 Ultimate

Hello and thanks a lot for your answers and sorry for being off so long.

I followed your suggestions, downloaded PW and started a recovery quick scan now. First thing I noticed is that PW does NOT see the disc divided into two partitions but as a 3TB unallocated one. From my guess this could be a good sign, no?

As soon as the quick scan is done I'll post the screen shot here. Thanks a lot! Martin
My System SpecsSystem Spec
14 May 2014   #8

Windows 7 Home Premium 32 bit

Yes, till it can find the partition/s the preview diskmap will show the 3TB as unallocated.

When the partition/s are shown and you select the partition/s the preview should show you the disk as it existed before .

Post the screenshot with the preview disk map after you select the partition/s by putting a check mark against them.
My System SpecsSystem Spec
14 May 2014   #9

Windows 7 Ultimate

Hello! The scan is done now, but unfortunately it does not look that good!?

First image shows PW without any partrition selected, second image with all selected.

Do you think there is a chance to reactivate the lost 3GB partition?

Thank you very much! Martin

Attached Thumbnails
3TB Hard disc became "unallocated", how to recover?-lost_partitions.jpg   3TB Hard disc became "unallocated", how to recover?-lost_partitions2.jpg  
My System SpecsSystem Spec
14 May 2014   #10

Windows 7 Home Premium 32 bit

Yes, it doesn't look good. It appears that the disk had undergone three format attempts giving rise to three boots. Only one of them may represent your last known state.(And you must be knowing better how your HDD looked like in its last working state.)

Now do not select all. Select one at a time and look at the disk map.

Does any one show your full disk without any unallocated space? That should be the right one.

I would suggest you post the three screenshots with only one boot selected in the order shown. Let me see all the three pictures before deciding what should be done.

It is already time for me to retire and I shall see it only after another six hours - that is if I wake up early.
My System SpecsSystem Spec

 3TB Hard disc became "unallocated", how to recover?

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