Some USB 2.0 audio devices that have an MIDI out port do not work correctly in Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2

Applies to: Windows VistaWindows 7Windows Server 2008 More

Symptoms


Consider the following scenario:
  • You attach a USB 2.0 audio device to a computer that is running Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2.
  • The USB 2.0 audio device has a MIDI out port.
In this scenario, the USB audio device may not work correctly. Additionally, the MIDI ports may not appear or not work as expected if you use software that supports the MIDI protocol.

Cause


This issue occurs because the USB Audio driver (Usbaudio.sys) has a hard-coded size limitation of 256 bytes for a MIDI packet. If a high-speed audio device requests over 256 bytes, the device does not work correctly.

Resolution


To resolve this issue, install this hotfix on the affected computers. After you apply this hotfix, the limitation is changed to 512 bytes.

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, you must be running Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2.

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 together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

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 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 MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separatelyin the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

Windows Vista and Windows Server 2008 file information notes


For all supported x86-based versions of Windows Vista and of Windows Server 2008
File nameFile versionFile sizeDateTimePlatform
Usbaudio.sys6.0.6002.2244373,21609-Jul-201013:59Not Applicable
For all supported IA-64-based versions of Windows Server 2008
File nameFile versionFile sizeDateTimePlatform
Usbaudio.sys6.0.6002.22443237,69609-Jul-201013:58Not Applicable
For all supported x64 Windows Vista Windows and of Server 2008
File nameFile versionFile sizeDateTimePlatform
Usbaudio.sys6.0.6002.2244398,94409-Jul-201014:19x64
Windows 7 and Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
  • 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 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. 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 7
File nameFile versionFile sizeDateTimePlatform
Usbaudio.sys6.1.7600.2073580,64016-Jun-201004:11Not Applicable
For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
File nameFile versionFile sizeDateTimePlatform
Usbaudio.sys6.1.7600.20735109,56816-Jun-201004:20x64
For all supported IA-64-based versions of Windows Server 2008 R2
File nameFile versionFile sizeDateTimePlatform
Usbaudio.sys6.1.7600.20735261,12016-Jun-201003:53Not Applicable

Status


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

More Information


For more information about software update terminology, 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

For more information about the MIDI protocol, visit the following Microsoft site: For more information about the Usbaudio.sys file, see the following Microsoft document:

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
File nameUpdate.mum
File versionNot Applicable
File size2,415
Date (UTC)09-Jul-2010
Time (UTC)23:29
PlatformNot Applicable
File nameX86_wdma_usb.inf_31bf3856ad364e35_6.0.6002.22443_none_6f5fb6e6cd3c8502.manifest
File versionNot Applicable
File size1,881
Date (UTC)09-Jul-2010
Time (UTC)23:29
PlatformNot Applicable
Additional files for all supported IA-64-based versions of Windows Server 2008
File nameIa64_wdma_usb.inf_31bf3856ad364e35_6.0.6002.22443_none_6f615adccd3a8dfe.manifest
File versionNot Applicable
File size1,882
Date (UTC)09-Jul-2010
Time (UTC)23:29
PlatformNot Applicable
File nameUpdate.mum
File versionNot Applicable
File size1,593
Date (UTC)09-Jul-2010
Time (UTC)23:29
PlatformNot Applicable
Additional files for all supported x64-based versions of Windows Vista and of Windows Server 2008
File nameAmd64_wdma_usb.inf_31bf3856ad364e35_6.0.6002.22443_none_cb7e526a8599f638.manifest
File versionNot Applicable
File size1,883
Date (UTC)09-Jul-2010
Time (UTC)23:30
PlatformNot Applicable
File nameUpdate.mum
File versionNot Applicable
File size2,433
Date (UTC)09-Jul-2010
Time (UTC)23:29
PlatformNot Applicable

Additional file information for Windows 7 and for Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7
File nameUpdate.mum
File versionNot applicable
File size1,628
Date (UTC)16-Jun-2010
Time (UTC)10:33
PlatformNot applicable
File nameX86_wdma_usb.inf_31bf3856ad364e35_6.1.7600.20735_none_6dade3de3123865c.manifest
File versionNot applicable
File size2,271
Date (UTC)16-Jun-2010
Time (UTC)06:49
PlatformNot applicable
Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
File nameFile versionFile sizeDateTimePlatform
Amd64_wdma_usb.inf_31bf3856ad364e35_6.1.7600.20735_none_c9cc7f61e980f792.manifestNot applicable2,27516-Jun-201007:37Not applicable
Update.mumNot applicable1,84216-Jun-201010:33Not applicable
Additional files for all supported IA-64-based versions of Windows Server 2008 R2
File nameIa64_wdma_usb.inf_31bf3856ad364e35_6.1.7600.20735_none_6daf87d431218f58.manifest
File versionNot applicable
File size2,273
Date (UTC)16-Jun-2010
Time (UTC)07:22
PlatformNot applicable
File nameUpdate.mum
File versionNot applicable
File size1,451
Date (UTC)16-Jun-2010
Time (UTC)10:33
PlatformNot applicable