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I use a USB key which is encrypted with BitLocker to store various data. I keep that key with me all the time.

What happens all the time is that I send my home computer to hibernate without ejecting the USB key first. Then I unplug the key and take it with me to work. When I get home, I resume my Windows session and even though the key is not plugged in, the drive still appears as mounted on the system.

I can also unmount the non-existing device with mountvol, but that only removes the drive letter. Windows will still think the device is plugged in. When I plug the key in, nothing happens.

The device's class ID is listed in mountvol output, but the device is not listed in the Disk Management panel.

Update: So the problem finally appeared again and I tried all the suggestions. Weavers suggestion seemed very promising but yielded no results. However, while browsing through Device Manager, I noticed that the device in question is still listed under "Portable Devices" and it is not greyed out.
Trying to uninstall that device gives me a "Confirm Device Uninstall" window that tells me it is uninstalling the device but never finishes. At this point, plugging the device into another USB slots has no effect.

The never-ending uninstall dialog

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5 Answers

Steps to remove "ghost" devices from a system

Open command prompt (CMD) and do the following steps (type the following without quotes):

  • type "set devmgr_show_nonpresent_devices=1"
  • type "start devmgmt.msc" Device manager should open.
  • select "view -> hidden devices"
  • open up "disk drives"
  • Remove any faded out items which match with your USB drive's identifier

    Reboot is not necessary in most cases, but might be a good idea.

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I like the approach, but without a reboot, the non-existent device does not disappear from the "My Computer" explorer view. Even though I removed exactly that device from the list in Device Manager. –  Oliver Salzburg Dec 6 '11 at 9:20
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Try clicking on "start button" -> right click "computer" -> click "properties" -> click "device manager" (in left column) -> then click the "scan for hardware changes" button ... This should refresh you usb key issue... I have looked for a way or script to run this buttons function automatically, but havent come up with much. If you find something , let me know!

Good luck!

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you can use Microsoft’s DevCon tool: > devcon rescan –  Synetech Jul 17 '11 at 18:30
    
I'll give that a try the next time the issue happens. Thanks. –  Oliver Salzburg Jul 18 '11 at 9:56
    
Scan for hardware changes did not remove the non-existent device in my case. –  Oliver Salzburg Dec 6 '11 at 9:15
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Plug the device to different USB port. Then Windows realizes it's indeed a newly plugged device, and the old ghost gets banished.

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That never worked for me, as Windows still thinks the device is already plugged it. Plugging it in again had no effect. –  Oliver Salzburg Aug 9 '11 at 17:28
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This might sound a little odd... but you shouldn't experience this issue if you shut your machine down fully instead of hibernating it.

When you hibernate, your machine attempts to remember everything "exactly" as is was plugged in for when you resume your session. When you use your USB away from your machine during the day, changes will be made to files stored in the hidden folder labelled system volume information on your USB, which your computer will have issues with when you start it back up.

Shutting down your machine fully will clear all this information about your USB from the systems memory, so it will be unaware of any changes and will assume that these files should be the way they are. It should also help speed up your system, as hibernation is quite resource intensive.

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At the very least he should be ejecting the device before suspending. He could also not even suspend it. –  Ramhound Dec 6 '11 at 12:19
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Check out USBDeview from Nirsoft. It has the ability to scan your system for all USB related devices and remove any defunct USB drivers. You probably might want to remove the USB drive first before using the tool.

http://www.nirsoft.net/utils/usb_devices_view.html

USBDeview is a software that lists all USB devices that connected to your computer, and allows you disable, enable or uninstall them.

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USBDeview did not list any devices that resemble the one in question. I assume this is at least partly due to the fact that I removed lots of devices through device manager already. –  Oliver Salzburg Dec 6 '11 at 9:27
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