USB storage device cannot be recognized or mounted on a computer that is running Windows 7 or Windows Server 2008 R2

Applies to: Windows 7 EnterpriseWindows 7 Home BasicWindows 7 Home Premium

Symptoms

Consider the following scenario:
  • You enable BitLocker Drive Encryption on a USB storage device that is connected to a Windows 7-based or a Windows Server 2008 R2-based computer.
  • When you run BitLocker To Go on the USB storage device, one of the following situations occurs and leads to an NTFS unexpected shutdown (also known as a dirty shutdown):
    • You disconnect the USB device without ejecting it.
    • The computer encounters a hard restart or shutdown, or encounters a power failure.
In this scenario, the USB storage device cannot be recognized or mounted on the computer. Additionally, when you run the Manage-bde.exe command on the removable storage device, the following error message is received:
ERROR: An error occurred (code 0x80070020):
The process cannot access the file because it is being used by another process.

Cause

This issue occurs because the virtualized boot block on the storage is created at a random location. Therefore, the virtualized boot block is overwritten by other files incorrectly.

Resolution

Update information

How to obtain this update

Microsoft Update
This update is available from the Windows Update website.
Microsoft Download Center
The following files are available for download from the Microsoft Download Center:
Operating systemUpdate
All supported x86-based versions of Windows 7Download Download the update package now.
All supported x64-based versions of Windows 7Download Download the update package now.
All supported x64-based versions of Windows Server 2008 R2Download Download the update package now.
All supported IA-64-based versions of Windows Server 2008 R2Download Download the update package now.
For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:
  • Windows 7
  • Windows 7 Service Pack 1 (SP1)
  • Windows Server 2008 R2
  • Windows Server 2008 R2 Service Pack 1 (SP1)
For more information about how to obtain a Windows 7 or Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

976932 Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2

Registry information

To apply this hotfix, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates