After you repeatedly connect and disconnect a USB device to a computer that is running Windows Vista or Windows Server 2008, the USB device is not detected

Consider the following scenario:

• You connect a USB 2.0 high-speed device to a USB port on a computer that is running Windows Vista or Windows Server 2008.
• The device is successfully detected by the computer.
• You repeatedly disconnect the device from the computer and then connect the device to the computer.

In this scenario, the port no longer works and the device is not detected by the computer.

This problem occurs when the USB selective suspend setting is enabled in the Power Options dialog box.

Note This problem may occur right after you start the computer.

This problem occurs because the USB root hub system device for the USB port incorrectly disconnects from the corresponding USB host controller.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, your computer must be running one of the following Windows operating systems:

• Windows Vista Service Pack 1 (SP1)
• Windows Vista Service Pack 2 (SP2)
• Windows Server 2008
• Windows Server 2008 Service Pack 2 (SP2)

For more information about how to obtain a Windows Vista service pack, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to obtain a Windows Server 2008 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

To use the hotfix in this package, 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.

File information

The English (United States) version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time and with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Vista and Windows Server 2008 file information notes

Important Windows Vista hotfixes and Windows Server 2008 hotfixes are included in the same packages. However, only "Windows Vista" is listed on the Hotfix Request page. To request the hotfix package that applies to one or both of these operating systems, select the hotfix that is listed under "Windows Vista" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

• The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

  Version	Product	SR_Level	Service branch
  6.0.600 0 . 20xxx	Windows Vista	RTM	LDR
  6.0.600 1 . 22xxx	Windows Vista and Windows Server 2008	SP1	LDR
  6.0.600 2 . 22xxx	Windows Vista and Windows Server 2008	SP2	LDR

• Service Pack 1 is integrated into the release version of Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008 and of Windows Vista

For all supported x64-based versions of Windows Server 2008 and of Windows Vista

For all supported IA-64-based versions of Windows Server 2008

To work around this problem, use one of the following methods.

Method 1

Restart the computer.

Method 2

1. Locate the USB root hub device that the USB 2.0 high-speed device connects to. To do this, follow these steps:
   1. In Device Manager, click Devices by connection on the View menu.
   2. Expand ACPI x86-based PC or ACPI x64-based PC.
      Note If the computer is running an x86-based operating system, ACPI x86-based PC is listed. If the computer is running an x64-based operating system, ACPI x64-based PC is listed.
   3. Expand Microsoft ACPI-Compliant System, and then expand PCI bus. You see one or more USB host controller devices whose names contain the word "Enhanced."
   4. Expand one of the USB host controller devices that you identified in step 1c, and then expand USB Root Hub. If the USB 2.0 high-speed device is listed, this is the USB root hub device that the USB 2.0 high-speed device connects to. If the USB 2.0 high-speed device is not listed, repeat step 1d on other USB host controller devices. Continue until you locate the USB root hub device that the USB 2.0 high-speed device connects to.
2. Right-click the USB host controller device that you identified in step 1d, and then click Disable.
3. Right-click the USB host controller device that you identified in step 1d, and then click Enable.
4. Close Device Manager.

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

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

Additional file information

Additional file information for Windows Vista and for Windows Server 2008

Additional files for all supported x86-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported x64-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported IA-64-based versions of Windows Server 2008