Win 10 Disk Mgmt not allowing me to assigning a drive letter - drive is there but options greyed out

New Contributor

Hello all,

      I am hooking up an external, healthy 1TB WIn 10 hard drive to a brand new HP all in one PC using an USB toaster-style adapter bridge, and new PC is also WIn 10.  Disk Mgmt "Sees" the disk but when I right click all the options to assign a drive letter are greyed out.  I tried multiple USB slots, etc.  Anyone know why this might be?  Seatools for Windows also sees it but I cannot assign a drive letter at all to grab some data.

      Note: Win 10 Disk Mgmt reports the disk as "GPT Protective Partition".  Is that the roadblock perhaps?

      Thanks for any help!!


~Charlie B.


2 Replies
best response confirmed by charlie88 (New Contributor)

@charlie88GPT protected partitions cannot be managed via disk management in Computer management. You could try to remove GPT protection using diskpart or other 3rd party disk management tools.
Note: actions below will clean all the data inside HDD, so if you need data inside, make sure that you have a backup first.
Diskpart is part of windows, so to launch it you only need to run CMD, type diskpart. You will enter application and in the application type:
List disk (this will display all the HDD's attached)
Select disk # (replace # with the number of the disk you want to work with)
Clean (this will remove GPT from the disk)

Continue disk configuration via Computer Management (if you have window open, refresh the view) as you are probably mostly familiar with.

@Arūnas Malūkas  Thanks very much for your response!  Yes I did some research on GPT which is there to avoid overwriting the drive when it is moved elsewhere.  I needed the Win 10 user data from the drive so none of the wipe options would work for me.  I ended up using Disk Genius to "recover" all the data I needed.  This was a bit of a pain to not have the HDD automatically show up as a drive letter (on my working WIn 10 machine) as well as the options for assigning  drive letter were also "Greyed" out in Diskpart.

      Thanks again and best of luck to you!