Problem with assigning of drive letter for external HDD

Discussion in 'Windows 7' started by zed87, Jul 5, 2010.

  1. zed87

    zed87 MDL Novice

    Jul 23, 2009
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    Everytime I turn on one of my external hard drives, my OS (W7 Ultimate x64) doesn't assign a drive letter automatically and I must do it manually. After this action is drive letter assigned until next system start.

    Does anybody know what might be a reason of this bevaviour? Thanks in advance for all your ideas ;)
     
  2. sam3971

    sam3971 MDL Guru

    Nov 14, 2008
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    Try these steps to see if it helps:

    1. Plug in and turn on the external USB hard drive
    2. Right mouse click on My Computer
    3. Left click on Manage
    4. Left click on Device Manager
    5. Expand the USB list
    6. Find the USB device for your USB Hard Drive (in my case it was the one that had no description)
    7. Right mouse click - Uninstall
    8. Turn off the external USB hard drive
    9. Turn on the external USB hard drive and let it find and install the driver
    10. It should work
     
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  3. Phazor

    Phazor MDL Expert

    Sep 1, 2009
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    Funny, this happened to me yesterday with one of my flashdrives.

    The problem was caused by my removing the drive letter from within drvmgmnt.

    From that point forward Windows would no longer auto-assign a letter because it thought i dont want that device to have one.

    I could fix it by assigning the letter which i removed from the flashdrive to another device.

    This has reset the whole thing and so the flashdrive automatically got the next free letter again.
     
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  4. sam3971

    sam3971 MDL Guru

    Nov 14, 2008
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    That is kinda ironic. I wonder if it is another potential bug in the win7 kernel system lol
     
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  5. zed87

    zed87 MDL Novice

    Jul 23, 2009
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    @sam3971: Thanks :) Now are all drive letters assigned correctly. I hope it'll work fine even one week later :D
     
  6. Phazor

    Phazor MDL Expert

    Sep 1, 2009
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    No, its not a bug, its a feature. (No kidding.)

    What happens is this:

    • You insert/power up the flashdrive/external drive

    • Windows registers the device in the registry and gives it the next free letter

    • Now you deliberately remove that letter from the device

    • Windows now has the info "No letter for this device" so next time the device comes online no letter will be assigned

    All in all pretty logical - the only thing thats unclear is why assigning the removed letter to some other device seems to reset this info.
     
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