External drive formatted as NTFS does not mount in Windows

Question

I have an external usb drive that has worked for a while now. I've been using it as a backup drive for deja-dup on Ubuntu and as a filehistory drive on Windows 8.1.

After a while, when I booted back into Windows the drive didn't show up anymore.

I opened disk management and saw that the drive has no drive letter. All that it says is "healthy (primary partition)". The drive mounts perfectly in Ubuntu.

I ran diskpart with the following output:

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          465 GB      0 B
  Disk 1    Online           29 GB      0 B
  Disk 2    Online          931 GB      0 B

DISKPART> list volume

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     E                       DVD-ROM         0 B  No Media
  Volume 1     D   System Rese  NTFS   Partition    350 MB  Healthy    System
  Volume 2     C                NTFS   Partition    397 GB  Healthy    Boot
  Volume 3     F   Christophe   exFAT  Removable     29 GB  Healthy

Fdisk in Ubuntu gives me the following result:

Disk /dev/sdb: 1000.2 GB, 1000204885504 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525167 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x13b5fd7e

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048  1953525166   976761559+  83  Linux

Gparted looks like this, however. Note that it says "NTFS" instead of "Linux".

Is there anything I can do to make it mountable again?

I have tried the drive in 2 Windows 8.1 Pc's and 1 windows vista pc. Neither work.

Also, when I try to to RMB on the drive in disk management to maybe assign a drive letter, all I can do is delete the volume.

Okay, so after further inspection of the URL in the comment I tried the following (disk 1 is the drive in question):

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          465 GB      0 B
  Disk 1    Online          931 GB      0 B

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    Primary            931 GB  1024 KB

DISKPART> select partition 1

Partition 1 is now the selected partition.

DISKPART> assign

There is no volume specified.
Please select a volume and try again.

DISKPART> list volume

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     E                       DVD-ROM         0 B  No Media
  Volume 1     D   System Rese  NTFS   Partition    350 MB  Healthy    System
  Volume 2     C                NTFS   Partition    397 GB  Healthy    Boot

Answer 1

Had the exact same problem. When I was using Ubuntu I made a partition (NTFS) and after a while installed Windows but the drive didn't mount. The problem was, there wasn't any drive letter assigned to it so it didn't mount. To resolve this: Click on the drive in Disk management. Then select change drive letter and assign a drive letter to it. That's it. It'll work.