An exclamation mark (!) may appear next to a USB device in Device Manager after you resume a Windows Vista-based portable computer from standby (S3)

Consider the following scenario:

• You are running a Windows Vista-based portable computer from a docking station.
• The computer has a USB device connected to it.
• You put the computer into standby (S3).
• You resume the computer from standby.

In this scenario, a yellow exclamation mark (!) may appear next to the USB device in Device Manager. This problem may occur if the status of the docked portable computer is changed when the system is in standby.

This is a timing issue between Plug and Play (PnP) enumeration and the USB device driver. When the system is resuming from standby, the system creates a new device object for the USB device. The system also removes PnP events for the old device object of the USB device. However, when the system resumes from the S3 standby state, the system experiences a delay in processing all the power events and all the PnP events. In this scenario, the USB driver may start to process the USB enumeration of the new device object before the system has received the PnP remove events for the old device object. If the USB enumeration process detects a duplicate device object for the USB device, the process waits for a predefined time period for the duplicate device object to be removed. If the device object is not removed before the predefined time period is exceeded, USB enumeration fails.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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 this specific problem. 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

No prerequisites are required.

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 version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Vista, x86-based versions

Windows Vista, 64-bit versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Vista Service Pack 1.