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MarkNixon

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Partition Inaccessible

Hi,

Windows 7 Pro.

When I open Computer Management/Disk Management, I see that my J: drive, which is no longer accessible in Explorer, is shown as a blank 540.89 GB partition on Disk 1, which it shares with the C: drive.

At the command prompt, typing J: produces: "The system cannot find the drive specified". All other drives, including networked drives can be accessed.

No method appears to be available in Disk Management to make it revert to its old accessible state and, in fact, its old Drive Letter (J) has been transferred to the 100 MB System Reserve partition also on Disk 1.

If I right-click on the partition, my choices are:-

      1. Mark partition as Active. (Seems inadvisable?)
      2. Change Drive Letter & Paths. All I get here is an error message saying "The operation failed to complete... etc."
      3. Format (I don't want to lose the files on this drive.)
      4. Delete Volume. Ditto.
      5. Properties. All I get here is the same error message as above.
      6. Help - doesn't!

I tried Paragon's Partition Manager 11 and it told me that BOTH the partitions on Disk 1 have 'Invalid' file systems, although Win 7 Disk Management shows C: as: "Healthy (System, Boot, Page File, Active, Crash Dump, Primary Partition)".

Can anyone tell me how to regain access to this logical drive?

Regards,

Mark Nixon
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Dhiraj Mutha
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Have you installed any other OS on the system? Is this HD is a seprate HDD or its a partition on a HD?
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I think the issue is that it has a drive letter assigned which means it was visible accessible at one point.  Did/do you have an application somewhat similar to truecrypt, pgp, etc that is supposed to manage the encryption of the data on this page.

Do you have an option to access the security tab on this J: dirve i.e. maybe the security settings got corrupted. such that your username/group no longer has access.

Take ownership might be what you need to use.
Be careful with any attempts if there should be data there of value..
Or bitlocker.
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dbrunton
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you can also try this  : http://www.ptdd.com/      
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MarkNixon

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Gentlemen,

Thank you all for your suggestions. I'll take them in order:-

      1. pspglb: No other OS on the machine - just Win 7 Pro. The partition in question is part of a HDD which also contains the boot partition.
      
      2. arnold: No encryption-managing applications installed. No way to access the security tabs on this drive; it is completely inaccessible.
      
      3. dbrunton: Thanks for the URL. I'll get TestDisk and see what it can do. I'll also read the Step by Step manual (RTFM is usually a good idea!).
      
      4. nobus: I'll try http://www.ptdd.com/ too. Thanks.
      
Regards,
      
Mark
Hi again,

Just running TestDisk. It has found that the two partitions on Disk 1 are conflicting:-

Disk /dev/sdb - 1000 GB / 931 GiB - CHS 121601 255 63
Current partition structure:
     Partition                  Start        End    Size in sectors

 1 P HPFS - NTFS              0  32 33    12 223 19     204800 [System Reserved]
 2 * HPFS - NTFS             12 223 20 50992 254 63  818995697 [C: Windows 7]
 3 P HPFS - NTFS          50992 214 39 121600 254 63 1134320065 [J: Old Windows]
Space conflict between the following two partitions
 2 * HPFS - NTFS             12 223 20 50992 254 63  818995697 [C: Windows 7]
 3 P HPFS - NTFS          50992 214 39 121600 254 63 1134320065 [J: Old Windows]

Now running its 'Deeper Search' - takes some hours as HDD is 1 TB...

So far, at 29% of Deeper Search Analysing Cylinders, the following appeared:-

      Warning: Incorrect number of heads/cylinder 16 (NTFS) != 255 (HD)
      Warning: Incorrect number of sectors per track 2 (NTFS) != 63 (HD)
        HPFS - NTFS           9868  34 23  9868 132 22       6174

Once the Deeper Search had finished, TestDisk showed a page:-

     Partition               Start        End    Size in sectors
* HPFS - NTFS              0  32 33    12 223 19     204800 [System Reserved]
D HPFS - NTFS             12 223 20 50992 214 38  818993152 [C: Windows 7]
D HPFS - NTFS           9868  34 23  9868 132 22       6174
P HPFS - NTFS          50992 214 39 121600 247 55 1134319616 [J: Old Windows]

- where: *= Primary Bootable
             D= Deleted Files
             P= Primary

I selected the first 'D' partition, the one with 818993152 sectors [C:Windows 7], and changed its status to 'P'.

The next screen showed:-

Disk /dev/sdb - 1000 GB / 931 GiB - CHS 121602 255 63

     Partition                  Start        End    Size in sectors

 1 * HPFS - NTFS              0  32 33    12 223 19     204800 [System Reserved]
 2 P HPFS - NTFS             12 223 20 50992 214 38  818993152 [C: Windows 7]
 3 P HPFS - NTFS          50992 214 39 121600 247 55 1134319616 [J: Old Windows]
 
At this point I seem to have a screen that agrees with the Step-by-Step, so I am going to take my courage in both hands and choose 'Write'...

Well, it worked perfectly! I now have a fully accessible & functional Disk 1.

Thank you, gentlemen, for your invaluable help. As always, Experts Exchange has come up trumps!

Kind Regards,

Mark