Windows 10: Windows 10 reassigns drive letter on every reboot

Discus and support Windows 10 reassigns drive letter on every reboot in Windows 10 Drivers and Hardware to solve the problem; For decades now I've been using USB ports on Windows computers to mount portable disk drives. While they are portable i.e., can be easily mounted on... Discussion in 'Windows 10 Drivers and Hardware' started by SnookRed, Apr 14, 2021.

  1. SnookRed Win User

    Windows 10 reassigns drive letter on every reboot


    For decades now I've been using USB ports on Windows computers to mount portable disk drives. While they are portable i.e., can be easily mounted on other computers they tend to remain on a given computer somewhat permanently. There are lots of reasons why it is desirable to have a a given drive letter always assigned to this device. Because Windows has always seemed to prefer choosing the letter lowest in the alphabet that is presently unassigned when dynamically assigning drive letters I choose the letter highest in the alphabet that is available to be assigned to this kind of drive. This keeps these semi permanent USB drives separate from those which I frequently mount and dismount for other purposes.


    This has always worked fine on Windows no matter what version until recently on Windows 10. Now when I change a drive letter, for example from D: to X:, on such a USB drive it only lasts until the system is shutdown or restarted. Something that, I think, may be contributing to this infuriating behavior might have begun when I attempted to to retire one of these devices and replace it with a new one. In that, is it possible that Windows knows that X: was assigned to a different drive than the one I now want to be X: and refuses to automatically assign X: to the new drive even though X: was removed using Disk Management from the old drive and assigned using Disk Management to the new drive?


    A hack I thought of trying, but decided to seek opinions from someone who might know better first, is to remove the registry keys named as \Dos\Devices\? from HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices which exist but are NOT associated with any permanently attached device. It also occurs to me that while registry keys do appear to be the cause of such a problem there are lots of others I'm unfamiliar with that could be causing the problem.


    Might someone be able to explain what's going on and how to resolve?

    :)
     
    SnookRed, Apr 14, 2021
    #1

  2. Drive Letters, will they be overwritten or reassigned?

    if you want to assign new letters to the new drives and keep you current drive letters assigned like they are now i suggest you take a screenshot of pc so you can manually reassign the various drive letters. i have the following saved in a folder on my backup drive called post os install. hope this helps.


    Windows 10 reassigns drive letter on every reboot [​IMG]


    fyi after fixing the drive letter assignments i hide the drive letters so everything lines up numerically and alphabetically
     
    xXWhacerXx, Apr 14, 2021
    #2
  3. mrje1 Win User
    Drive Letters, will they be overwritten or reassigned?

    Thank you for your help and assistance xXWhacerXx! If you can clarify this first, because I believe I saw a warning on this that by changing the drive letter can ruin other things that are mapped to it. I would like to not change the drive letters once they are assigned, but if you are not having any problems I guess that could be something that I saw wrong.

    Also, do you think that having the drive letters as explained before and plugging in the other ones that had the same drive letter will overwrite the new ones or change them automatically?
     
    mrje1, Apr 14, 2021
    #3
  4. Windows 10 reassigns drive letter on every reboot

    WD external drive letter change

    Hi @WilliamSlessor!

    I'm sorry to hear about the confusion with the external drive. What I would suggest is to go in Disk Management and try to reassign the letters on both drives with a third one, and then go back to the original letters. For instance - change the G:G: drive to
    M:, and then reassign it as G: again.

    You can follow the steps described in this KB article:

    http://products.wdc.com/support/kb.ashx?id=T1tsut

    Hope this helps and let us know how it went.
     
    MightyMiro_WD, Apr 14, 2021
    #4
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Windows 10 reassigns drive letter on every reboot

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