When a User-Mode Driver Framework (UMDF) driver that uses the Windows SideShow class extension processes a command asynchronously, the class extension may return a false error without fully processing the command. This problem may occur when the incoming input/output control (IOCTL) is not passed to the class extension component immediately. This problem may also occur when the IOCTL is from a sequential queue.

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This problem occurs if the developer’s driver impersonates outside the scope of the original OnXxx callback. When this happens, the impersonation fails. This failure can cause the driver to return an incorrect error. To correctly handle incoming IOCTLs, the SideShow class extension component requires successful use of impersonation.

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Hotfix information

A supported hotfix is now 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 service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:Note If additional issues occur or 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. To create a separate service request, visit the following Microsoft Web site:

Prerequisites

No prerequisites are required.

Restart requirement

You do not have to restart your computer after you apply this hotfix.

Hotfix replacement Information

This hotfix does not replace any other hotfixes.

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, 32-bit versions

File name	File version	File size	Date	Time	Platform
Wudfcoinstaller.dll	6.0.6000.20546	87,552	28-Feb-2007	03:08	x86
Wudfhost.exe	6.0.6000.20546	144,384	28-Feb-2007	02:14	x86
Wudfpf.sys	6.0.6000.20546	52,224	28-Feb-2007	02:14	x86
Wudfplatform.dll	6.0.6000.20546	181,760	28-Feb-2007	03:08	x86
Wudfrd.sys	6.0.6000.20546	82,688	28-Feb-2007	02:14	Not Applicable
Wudfsvc.dll	6.0.6000.20546	55,296	28-Feb-2007	03:08	x86
Wudfx.dll	6.0.6000.20546	310,784	28-Feb-2007	03:08	x86
Wudfx.mof	Not Applicable	48,262	07-Jan-2007	05:46	Not Applicable
Wudfxuninstall.mof	Not Applicable	475	07-Jan-2007	05:46	Not Applicable

Windows Vista, 64-bit versions

File name	File version	File size	Date	Time	Platform
Wudfcoinstaller.dll	6.0.6000.20546	89,600	28-Feb-2007	04:20	x64
Wudfhost.exe	6.0.6000.20546	168,448	28-Feb-2007	02:34	x64
Wudfpf.sys	6.0.6000.20546	65,024	28-Feb-2007	02:34	x64
Wudfplatform.dll	6.0.6000.20546	202,752	28-Feb-2007	04:20	x64
Wudfrd.sys	6.0.6000.20546	108,032	28-Feb-2007	02:34	x64
Wudfsvc.dll	6.0.6000.20546	66,560	28-Feb-2007	04:20	x64
Wudfx.dll	6.0.6000.20546	382,976	28-Feb-2007	04:20	x64
Wudfx.mof	Not Applicable	48,262	07-Jan-2007	05:46	Not Applicable
Wudfxuninstall.mof	Not Applicable	475	07-Jan-2007	05:46	Not Applicable

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

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

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