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Windows 10 changing assigned drive letters after reboot RRS feed

  • Question

  • I am having problems with Windows 10 64 pro reassigning drive letters on a USB memory card reader.  Specifically it is a Dynex model DX-CRD12 internal all in one card reader.  It interfaces to my computer through an internal  USB interface.  Using the disk management tool I assigned drive letters to each of the five memory card readers.  On this Windows 10 computer randomly during startup Windows will reassign the drive letters which conflict with my network drives.  This requires me to go in and change the drive letters again.  I have seen several posts on the Internet with others having the same problem.  One person suggested making the change directly in the registry which I have tried but that seems to make no difference.  I have been using this specific card reader on this same computer running Windows 7 64 pro for years and never had any problems.   I also have this same card reader installed on another very similar Windows 10 64 pro computer and it does not seem to be doing it.  It makes me wonder if there is something specific to this motherboard.  They are both Asus motherboards but slightly different models.

    Any suggestions would be appreciated.

    Sparky

    Thursday, November 5, 2015 3:28 PM

Answers

  • Something to consider trying is to remove third party drivers for your card reader and let Microsoft provide drivers for the device. It sounds as though when the computer boots the card reader is being detected as a “new device” each time and thus getting the next available drive letters. You may also want to try disabling power management on your USB chipset for the same reason.

    Brandon
    Windows Outreach Team- IT Pro
    Windows for IT Pros at TechNet

    Thursday, December 3, 2015 8:30 PM
    Moderator

All replies

  • This is now happening every time I shut down and start back up.  It does not seem to happen on a reboot.  I see others having this problem on other OS's Windows 2008 server etc.  This is a major pain.  Please help.

    Sparky

    Friday, November 6, 2015 12:05 PM
  • I believe the driver letter assignment done through Disk Management is to the (mounted) volume itself. I do not know specifically how your card reader is enumerated, but it may be that the slot is what Windows assigns a driver letter rather than the card inside. Some card readers end up working this way where they can get a drive letter even if they are empty. So if this is the case, no assignment in Disk Management may actually work IF it is the slot that gets the letter, and then it mounts the volume afterwards. This also causes deployment issues on some hardware where a card reader can take the disk number or drive letter of the HDD, even if empty. For situations like this you either:

    1. Re-assign the card reader volumes to other letters at boot and/or fix network drive mappings (as needed)
    2. Make sure your network mappings will not interfere with possible physical mappings.

    Alternatively, if the client supports it, use UNC or Symbolic Link mount points for network shares rather than drive letters.


    • Edited by Tripredacus Friday, November 6, 2015 5:05 PM
    Friday, November 6, 2015 5:05 PM
  • Hi,

    In addition, Try clearing the hidden attributes of these problematic drives by using diskpart command.

    Diskpart

    LIST VOLUME

    SELECT VOLUME n

    ATTRIBUTES VOLUME CLEAR HIDDEN

    .

    .

    (Repeat above steps for other volumes)

    EXIT

    and reboot your computer.

    Regards,

    D. Wu


    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Tuesday, November 10, 2015 9:54 AM
    Moderator
  • Thanks.  I tried this suggestion already.  I get an error that you cannot perform this action on removable drives.
    Tuesday, November 10, 2015 11:51 AM
  • Thanks for this response.  You are correct that the drive letter is assigned to the slot not just the media.  I assign the slots in Disk Management and when I do a colt restart it reassigns them.  I am still having the problem.
    Tuesday, November 10, 2015 11:53 AM
  • Hi,

    Try using disk part to assign driver letter to these devices, use the V, W, and Z instead of common word like D, E. If this still doesn’t work, as a workaround, we can try using an autorun bat file to assign letters to these devices based on GUID.

    Regards,

    D. Wu


    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Monday, November 16, 2015 2:31 AM
    Moderator
  • Thanks for the response.  The configuration I have and have been using for years on Windows 7 is my network drives are labeled G, H, & I.  The USB memory slots are J, K, L, & M.  So I am not using the lower letters.  When I power back on the USB memory slots and getting changed to G, H, I, & J overwriting my network drives.  Currently as a band-aid am using a service utility to assign the letters upon reboot.  But I would prefer not to have to use that.  What is puzzling and makes me think this is a Windows 10 issue is I have been using this configuration for years with Windows 7 assigning the drive letters with the MS disk management utility and it worked fine.  I also have another very similar computers (slightly different motherboard) running Windows 10 and it is running fine. That is what doesn't make any sense.
    Monday, November 16, 2015 12:36 PM
  • Something to consider trying is to remove third party drivers for your card reader and let Microsoft provide drivers for the device. It sounds as though when the computer boots the card reader is being detected as a “new device” each time and thus getting the next available drive letters. You may also want to try disabling power management on your USB chipset for the same reason.

    Brandon
    Windows Outreach Team- IT Pro
    Windows for IT Pros at TechNet

    Thursday, December 3, 2015 8:30 PM
    Moderator
  • My friends are having this issue with 2 removable hard drives.  I reassigned the correct drive letters; after reboot they were changed again.  This is an issue with Windows 10 that needs to be fixed. 
    Wednesday, January 18, 2017 10:39 PM
  • Think what I have to do when mine does that. I have 10 yes ten seperate hard drives  I think it is win 10 that is the problem.
    • Edited by fatherted Friday, March 2, 2018 12:58 PM
    Friday, March 2, 2018 12:57 PM
  • I understand, I have 36 volumes to assign, 14 are seperate oprerating systems running with different AV's no more letters to assign, The problem is every time I remove the clutter of assigned letters with disk Mgt or third party disk mgt tool (like AOmei or Easeaus) and reduce it down to C, D, E & F drive Win10 reassigns all others bootable drives with letters again.  There is however an option to hide the  partion but unfortunately I have to unhide it every time I want access, so still working on a solution. Just thinking aloud if bootable volumes were GPT not MBR would this solve the issue? 
    Friday, April 27, 2018 8:56 AM
  • Thank you
    Thursday, November 14, 2019 11:06 PM