Not recognising USB HDD,s


  1. Posts : 14
    Win 7 home premium x64
       #1

    Not recognising USB HDD,s


    Hi all.

    As of a few days ago, computer not recognising plugged in USB hard drives.
    Have to assign drive letter via Disk Management to access the drive.
    I don't understand why this should suddenly occur. I am not aware of anything untoward happening that results in this very annoying glitch.
    Ideas most welcome.

    Thanks in advance.
      My Computer


  2. Posts : 12,012
    Windows 7 Home Premium SP1, 64-bit
       #2

    Here's some ideas:

    Use another cable

    Use another USB port

    Run the drive manufacturer's diagnostic tool

    Not sure what drivers USB drives use, but you might try to remove any drivers in Device Manager and then do a new install as if you just bought the thing.
      My Computer


  3. Posts : 14
    Win 7 home premium x64
    Thread Starter
       #3

    Hi.
    Should have been more coherent. The drive does show in Disk Management but drive letter is not assigned and therefore it is not accessible in win explorer for example, until drive letter is assigned. This happens with all my USB drives regardless of port used.
      My Computer


  4. Posts : 7,055
    Windows 7 Home Premium 32 bit
       #4

    Your early morning worksheet. :)

    Plug out all USB HDDs.

    Start > All Programs > Accessories > Right click on Command Prompt and Run as administrator.
    Then
    diskpart [ENTER]
    Against the DISKPART prompt
    automount [ENTER]
    Does it say "automatic mounting of new volumes disabled" ? Then
    automount enable [ENTER]
    "automatic mounting of new volumes enabled"

    Close Command Window.

    Now plug-in your ext. HDDs

    Problem resolved??? Post report.
      My Computer


  5. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #5

    @jumanji

    Would it be helpful after following your instructions to reboot?
      My Computer


  6. Posts : 7,055
    Windows 7 Home Premium 32 bit
       #6

    Usually we always recommend to reboot after doing any alteration. Some do not require a reboot.. I do not remember whether a reboot is required in this case. I have to run it and check. You may also disable and then enable and check. Thanks for bringing this out . To make sure, the OP may reboot and then plug in his HDDs.
      My Computer


  7. Posts : 14
    Win 7 home premium x64
    Thread Starter
       #7

    Jumanji.

    Followed your instructions and indeed auto mounting was disabled.
    All external HDD's now have drive letters attached.
    I would like to know why auto mounting was disabled, but I suppose that's Windows for you.

    Thanks a lot.
      My Computer


  8. Posts : 7,055
    Windows 7 Home Premium 32 bit
       #8

    grasmith said:
    Jumanji....I would like to know why auto mounting was disabled, but I suppose that's Windows for you.....
    Neither men nor machines are 100% perfect.:)

    Some random event had caused the registry value HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MountMgr\NoAutoMount to change
    from 0 to 1 . We just reversed it.

    What that event was in your case is hard to guess.

    In Nov 2014, when Lady Fitzgerald was setting up her new Lenovo laptop, she had the same problem. Considering that it was a brand new laptop, it is even harder to guess.:)

    Anyway, I have added your question to the "100 things to do research" list, but I don't know when I will do it. I am not perfect either.
      My Computer


 

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