I've plugged an external hard disk on my computers. The device has been detected, but isn't shown on explorer. It is the same situation on both windows 7 and windows 10.

Detected / installed because it was shown in control panel > Devices and Printers. Also because I've found it using the list disk command line and it should be the Disk 1 :

Microsoft DiskPart version 10.0.10586

Copyright (C) 1999-2013 Microsoft Corporation.

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          238 GB      0 B        *
  Disk 1    Online          465 GB   127 MB        *

Unrecognized because it seems that the Partition 2 has unknown file system type. So it cannot be recognized by windows.

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    System             200 MB    20 KB
  Partition 2    Unknown            465 GB   200 MB

Can somebody help me to resolve this problem without clean the data in the hard disk ?

Disk manager Toshiba


I tested the hard disk format type on OSX. And its type Apple_HFS as you can see at /dev/disk2.

Air-de-xx:~ xx$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage Macintosh HD            120.5 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1 (internal, virtual):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Macintosh HD           +120.1 GB   disk1
                                 Logical Volume on disk0s2
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS MEMUP                   499.8 GB   disk2s2
  • Please provide an English translation of the information you have provided. Verify you have authorization to plug this device into the computer, it is a trivial task, to configure Windows in such a way that unapproved storage devices won't be mounted.
    – Ramhound
    Feb 22, 2016 at 17:04
  • It's almost certainly being disallowed from mounting. That said, what does diskmgmt.msc look like?
    – Ben N
    Feb 22, 2016 at 17:08
  • I don't have access to diskmgmt.msc. It is restricted by a strategy. I need to call an administrator to do it. Let's give up this question and move on if you don't mind. @BenN Feb 23, 2016 at 8:18
  • The disk seems to work perfectly, but the partition type for the second partition is ntot recognised. This means that windows does not recognise it and it cannot mount something it does not recognise. Now on how to fix it. Step 1 would be te determine which filesystem it is. ext2? ext3? Reiser? some encrypted format? HFS? After we know that we can continue to work to a solution.
    – Hennes
    Feb 23, 2016 at 10:42
  • (continued). Since windows does not recognise it try booting another OS froma live CD (or pendrive). E.g. one of the many linux live CDs. Then do the modern equivalent of a fdisk -l).
    – Hennes
    Feb 23, 2016 at 10:44

3 Answers 3


What was the hard drive used for previously? Make sure the hard drive is formatted in NTFS, Fat32, or eXFat so that it is readable by Windows. Windows can't read file systems that are formatted for Mac or Linux. It may also not be mounted.

Guide to mount drives: http://windows.microsoft.com/en-us/windows/mount-dismount-drive#1TC=windows-7

  • select disk 2 followed by list partition would show whether the file system is recognized.
    – Ben N
    Feb 22, 2016 at 17:28
  • If the file system was not being recognized the behavior would be entirely different. Based on the description the volumes are not even attempting to be mount
    – Ramhound
    Feb 22, 2016 at 17:49
  • @Ramhound What kind of behavior would be happening then of the file system was unreadable? Feb 22, 2016 at 18:59
  • @GabeZimbric link is dead. Sep 4, 2016 at 12:51

Try changing the external hard-disk case or plug it in through another external USB hard-disk connector (and not through its own case circuit), to make sure if the hard-disk case circuit is still working and not gone out of order.

  • It is working elseo it could not comminicate with it, detect GTP partitioning and the EFI system partition.
    – Hennes
    Feb 23, 2016 at 10:39
  • sorry mistyped!, I meant to test if the hdd case circuit is working, and not the hdd itself - already corrected my reply above. Since its possible that the system detects the hdd when connected through a malfunctioned case or connector but unable to read it.
    – Umar T.
    Feb 23, 2016 at 11:07

Please check the disk manager. There are multiple ways to access it, and depending on the version of Windows that you have, the steps might be slightly different

On most windows
1. Open Windows Explorer > Right-click My Computer/or This PC > Manage
Or WindowsKey + R > Type diskmgmt.msc
2. Locate the disk partition in question > Right-click "Change Drive Letter and Paths"
3. Make sure there is a drive letter associated to the disk, or click Add to create one
4. See if you can access the disk after a disk letter had been established

Here is a quick example to Win7 steps enter link description here

  • Option "Change Drive Letter and Paths" is disabled Feb 23, 2016 at 9:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.