Audio-related applications may experience exception or function failure in Terminal sessions in Windows Server 2008 or in Windows Vista Service Pack 1

Consider the following scenario:

• An audio-related application manages a full duplex audio device in Windows Server 2008 or in Windows Vista Service Pack 1 (SP1) Terminal sessions. This audio device supports audio recording and playback.
• This application performs audio recording and then exits.
• This application tries to perform audio playback.

In this scenario, the application experiences an error and cannot perform audio playback. You must disconnect and then reconnect the Terminal session to recover from this problem.

This problem occurs because of the endpoint caching feature. Because of this feature, the audio engine does not send the message to close to the audio device immediately after the audio-related application ends in the Terminal session. If the audio-related application is opened again, it experiences an exception because the device is still open.

The endpoint caching feature was introduced in Windows Server 2008 and in Windows Vista for Terminal session performance optimization purposes.

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.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the �Hotfix Request� page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

To apply this hotfix on a Windows Vista-based computer, you must have Windows Vista SP1 installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base: No prerequisites are required for Windows Server 2008-based computers.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

Post-installation instructions

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
After you install hotfix 961918, you must disable the endpoint caching feature. To do this, change the following registry subkey value to .

Location:
Name:
Type: REG_BINARY
Value: 0b 00 00 00 02 00 00 00 ff ff (default value)

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 and Windows Server 2008 file information notes

The .manifest files and the .mum files that are installed in each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. These files and their associated .cat (security catalog) files are critical to maintaining the state of the updated component. The .cat files are signed with a Microsoft digital signature. The attributes of these security files are not listed.

For all supported 32-bit versions of Windows Server 2008 and of Windows Vista

For all supported 64-bit versions of Windows Server 2008 and of Windows Vista

For all supported Itanium-based versions of Windows Server 2008

To work around this problem, you have to disconnect the Terminal session, and then reconnect it.

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

Additional file information for Windows Server 2008 and Windows Vista

Additional files for all supported 32-bit versions of Windows Server 2008 and of Windows Vista

Additional files for all supported 64-bit versions of Windows Server 2008 and of Windows Vista

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