Symptoms

Consider the following scenario:

  • You run a 32-bit application on a computer that is running a 64-bit version of Windows 7 or Windows Server 2008 R2.

  • The application uses the network basic input/output system (NetBIOS) API to communicate with a remote computer.

  • The NetBIOS session is ended or closed while the application is receiving data.

In this scenario, the application does not receive notifications that the session has ended or closed and does not try to reestablish the session. You have to restart the application to recover from this issue.

Notes

  • You do not experience this issue when you run the 32-bit application on a computer that is running a 32-bit version of Windows 7.

  • You do not experience this issue if you recompile the application as a 64-bit application and then run it on a computer that is running a 64-bit version of Windows 7 or Windows Server 2008 R2.


Cause

This issue occurs because of an error in the NetBIOS interface (Netbios.sys) driver. When the Netbios.sys driver is receiving data, the driver does not convert the network connection block (NCB) structure from 64-bit to 32-bit when the session is abandoned. Because the 32-bit application cannot understand the 64-bit NCB structure, the issue described in the Symptoms section occurs.

Resolution

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that 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 website:

http://support.microsoft.com/contactus/?ws=supportNote 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 one of the following operating systems:

  • Windows 7

  • Windows 7 Service Pack 1 (SP1)

  • Windows Server 2008 R2

  • Windows Server 2008 R2 Service Pack 1 (SP1)

For more information about how to obtain a Windows 7 or Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

976932 Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

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 global 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.

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 files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

    Version

    Product

    SR_Level

    Service branch

    6.1.760
    0.
    16xxx

    Windows 7 and Windows Server 2008 R2

    RTM

    GDR

    6.1.760
    0.
    21xxx

    Windows 7 and Windows Server 2008 R2

    RTM

    LDR

    6.1.760
    1.
    21xxx

    Windows 7 and Windows Server 2008 R2

    SP1

    LDR

  • 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 x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Netbios.sys

6.1.7600.21097

44,544

24-Nov-2011

05:25

x64

Wshnetbs.dll

6.1.7600.16385

13,312

14-Jul-2009

01:41

x64

Netbios.sys

6.1.7601.21866

44,544

24-Nov-2011

05:23

x64

Wshnetbs.dll

6.1.7600.16385

13,312

14-Jul-2009

01:41

x64

For all supported IA-64–based versions of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Netbios.sys

6.1.7600.21097

136,704

24-Nov-2011

04:27

IA-64

Wshnetbs.dll

6.1.7600.16385

31,744

14-Jul-2009

01:50

IA-64

Netbios.sys

6.1.7601.21866

136,704

24-Nov-2011

04:17

IA-64

Wshnetbs.dll

6.1.7600.16385

31,744

14-Jul-2009

01:50

IA-64

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 a similar issue, click the following article number to view the article in the Microsoft Knowledge Base:

940480 A 32-bit application cannot use the NetBIOS API to receive data on a computer that is running a 64-bit version of Windows Vista For more information about a similar issue, click the following article number to view the article in the Microsoft Knowledge Base:

940074 A 32-bit application cannot use the NetBIOS API to receive data on a computer that is running a 64-bit version of Windows Server 2003

Additional file information

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

Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

Amd64_043049066698287fbad551d86c88953b_31bf3856ad364e35_6.1.7601.21866_none_999550a3836af6c5.manifest

File version

Not applicable

File size

699

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

File name

Amd64_132816a25ba2731aac0fe6be2e007125_31bf3856ad364e35_6.1.7600.21097_none_d4090e1eedfb8742.manifest

File version

Not applicable

File size

699

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

File name

Amd64_microsoft-windows-netbios_31bf3856ad364e35_6.1.7600.21097_none_b65758e49df468d5.manifest

File version

Not applicable

File size

4,308

Date (UTC)

24-Nov-2011

Time (UTC)

18:50

Platform

Not applicable

File name

Amd64_microsoft-windows-netbios_31bf3856ad364e35_6.1.7601.21866_none_b85d4f289b03317c.manifest

File version

Not applicable

File size

4,308

Date (UTC)

24-Nov-2011

Time (UTC)

18:50

Platform

Not applicable

File name

Update.mum

File version

Not applicable

File size

3,215

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

Additional files for all supported IA-64–based versions of Windows Server 2008 R2

File name

Ia64_1ba857e66fbf801e529f25449ede14db_31bf3856ad364e35_6.1.7600.21097_none_1d85e242f192115e.manifest

File version

Not applicable

File size

697

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

File name

Ia64_d1db4266ead8013a875955f90f79714e_31bf3856ad364e35_6.1.7601.21866_none_96fe9e46bd670cb2.manifest

File version

Not applicable

File size

697

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

File name

Ia64_microsoft-windows-netbios_31bf3856ad364e35_6.1.7600.21097_none_5a3a6156e595009b.manifest

File version

Not applicable

File size

4,307

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

File name

Ia64_microsoft-windows-netbios_31bf3856ad364e35_6.1.7601.21866_none_5c40579ae2a3c942.manifest

File version

Not applicable

File size

4,307

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

File name

Update.mum

File version

Not applicable

File size

1,947

Date (UTC)

24-Nov-2011

Time (UTC)

16:50

Platform

Not applicable

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