Microsoft KB Archive/936004

= A USB telephony device that is installed on a Windows Vista-based computer is unexpectedly set as the default audio device =

Article ID: 936004

Article Last Modified on 8/28/2007

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APPLIES TO


 * Windows Vista Ultimate
 * Windows Vista Home Premium
 * Windows Vista Home Basic
 * Windows Vista Enterprise
 * Windows Vista Business
 * Windows Vista Business 64-bit Edition
 * Windows Vista Ultimate 64-bit Edition
 * Windows Vista Home Premium 64-bit Edition
 * Windows Vista Home Basic 64-bit Edition
 * Windows Vista Enterprise 64-bit Edition

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SYMPTOMS
After you install a universal serial bus (USB) telephony device on a Windows Vista-based computer, this device is unexpectedly set as the default audio device. The USB telephony device can be a USB telephone, a USB handset, or a USB headset. This behavior occurs even though other audio devices are already installed on the computer.

In this situation, the computer cannot correctly play media or record media.



CAUSE
This problem occurs because the system does not check the device type of the newly installed audio device. Instead, the system sets the newly installed device as the default audio device even though the device is a telephony device.



Update information
The following files are available for download from the Microsoft Download Center:

Windows Vista, 32-bit versions
Download the 936004 package now.

Windows Vista, 64-bit versions
Download the 936004 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
No prerequisites are required.

Restart requirement
You must restart the computer after you apply this update.

Update replacement information
This update does not replace any other updates.

File information
The English version of this update 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, 64-bit versions


WORKAROUND
To work around this problem, reset the device of your choice as the default audio device. To do this, follow these steps:
 * 1) Click Start, and then click Control Panel.
 * 2) In Control Panel, double-click Sound.
 * 3) On the Playback tab, click the audio device that you want in the Select a playback device below to modify its settings list, and then click Set Default.
 * 4) On the Recording tab, click the audio device that you want in the Select a playback device below to modify its settings list, and then click Set Default.
 * 5) Click OK.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
For more information about the same problem in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:

935708 A USB telephony device that is installed on a Windows XP-based computer is unexpectedly set as the default audio device

For more information about how to determine an audio device type, visit the following Microsoft Web site:

http://msdn2.microsoft.com/en-us/library/ms790325.aspx

For more information, 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

Keywords: kbbug kbfix kbqfe kbpubtypekc kbexpertiseinter kbexpertisebeginner kbhotfixserver kbwinvistapostrtmfix KB936004

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