I have an external USB drive I use for file backups in my home network (for both Windows and OSX machines). It's normally plugged into my wireless router (TP-Link Archer C9). It works fine but I would like to do some faster file transfers so I plugged it into my Windows 10 machine via USB and Windows won't assign it a drive letter. DISKPART says "type" is "unknown" and, unfortunately, I don't remember what I had formatted it as.

I attempted to follow the answer for this question (How do I mount the EFI partition on Windows 8.1 so that it is readable and writeable?) but DISKPART says there's no volume for me to mount.

DISKPART> list volume

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     E                       DVD-ROM         0 B  No Media
  Volume 1         System Rese  NTFS   Partition    100 MB  Healthy    System
  Volume 2     C                NTFS   Partition    930 GB  Healthy    Boot
  Volume 3                      NTFS   Partition    450 MB  Healthy    Hidden
  Volume 4     D   Samsung SSD  NTFS   Partition    232 GB  Healthy
  Volume 5     F   SEAGATE      FAT32  Partition   1863 GB  Healthy
  Volume 6         EFI          FAT32  Partition    200 MB  Healthy    Hidden

DISKPART> list part

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    System             200 MB    20 KB
* Partition 2    Unknown            931 GB   200 MB

DISKPART> assign

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

Here's look the Disk Management screen. The highlighted volume is the one I'd like access to. I don't know why I can't see it in DISKPART.

Disk management

  • You haven't made the context clear. I have an external drive I use for file backups in my home network (for both Windows and OSX machines). So how was it connected to / used by your "machines"? Was it like a drive attached to a router or something? so I plugged it into my Windows 10 machine so you mean you've disassembled it and connect it to a SATA port or what? You probably do NOT want to try mounting the ESP anyway btw.
    – Tom Yan
    Jul 17, 2016 at 20:08
  • Yes, sorry, it was connected to my router (a TP-Link Archer C9). I've unplugged it from the router and plugged it into my computer via USB 3.
    – pcg79
    Jul 17, 2016 at 22:57
  • I'd recommend you right-click on the volume in Disk management and try to assign a different drive letter to the HDD. This could help you access the unknown volume and make it properly recognized by Windows. I'd also recommend you keep a copy of the backups somewhere else as well, especially if you use this particular external drive with different devices (the computer and the router). Swapping the devices could corrupt the file system and lead to potentail data loss., so be careful. Hope this helps. Keep us posted! :) Jul 20, 2016 at 12:34
  • Probably another thing I should've mentioned - right clicking on the volume produces an almost entirely grayed out menu. I can't assign a drive letter.
    – pcg79
    Jul 21, 2016 at 14:35

2 Answers 2


Many routers are based on Linux and are therefore likely to use a filesystem like Ext4 or some other filesystem that Windows does not by default know how to read.

I would boot my Windows PC from a Linux live USB device or DVD as it will have tools to identify the partition. Likely it will automount them.

Having identified the filesystem as Ext4, I would then either use Linux to work with the files or to copy the files to an existing NTFS or FAT partition on the PC's main hard disk. Alternatively install support for EXT4 on Windows


Its partition ID is incorrect.

select disk #
select partition #
set id=#

Get ID from: https://www.win.tue.nl/~aeb/partitions/partition_types-1.html

eg: 07 for NTFS, 0b or 0c for Fat32, ee/ef for EFI

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