Applies ToWindows 7 Enterprise Windows 7 Professional Windows 7 Ultimate Windows 7 Home Basic Windows 7 Home Premium Windows 7 Starter Windows Server 2008 R2 Datacenter Windows Server 2008 R2 Enterprise Windows Server 2008 R2 Standard Windows Server 2008 R2 for Itanium-Based Systems Windows Server 2008 R2 Foundation Windows Server 2008 R2 Web Edition

Symptoms

Consider the following scenario:

  • You enable the TCP/IP Offloading feature on a computer that is running Windows 7 or Windows Server 2008 R2.

  • A network adapter that supports TCP/IP Offloading is installed on the computer.

  • The network adapter does not support the TCP Selective Acknowledgements (SACK) option.

In this scenario, the TCP SACK option for offloaded TCP connections on the network adapter is always set to true. Therefore, you experience poor performance in busy network environments.

Resolution

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 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 apply this hotfix, 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.

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 notesImportant 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, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:

    Version

    Product

    Milestone

    Service branch

    6.1.760 0.21xxx

    Windows 7 and Windows Server 2008 R2

    RTM

    LDR

    6.1.760 1.22xxx

    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 7 and for Windows Server 2008 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. 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 name

File version

File size

Date

Time

Platform

Netio.sys

6.1.7601.22172

240,488

23-Nov-2012

05:49

x86

Fwpkclnt.sys

6.1.7600.21380

187,224

23-Nov-2012

05:10

x86

Tcpip.sys

6.1.7600.21380

1,303,912

23-Nov-2012

05:10

x86

Fwpkclnt.sys

6.1.7601.22172

187,736

23-Nov-2012

05:49

x86

Tcpip.sys

6.1.7601.22172

1,307,992

23-Nov-2012

05:49

x86

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Netio.sys

6.1.7601.22172

376,664

23-Nov-2012

05:59

x64

Fwpkclnt.sys

6.1.7600.21380

288,104

23-Nov-2012

05:53

x64

Tcpip.sys

6.1.7600.21380

1,878,376

23-Nov-2012

05:53

x64

Fwpkclnt.sys

6.1.7601.22172

288,616

23-Nov-2012

05:59

x64

Tcpip.sys

6.1.7601.22172

1,902,424

23-Nov-2012

05:59

x64

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

File name

File version

File size

Date

Time

Platform

Netio.sys

6.1.7601.22172

711,000

23-Nov-2012

05:07

IA-64

Fwpkclnt.sys

6.1.7600.21380

482,648

23-Nov-2012

04:41

IA-64

Tcpip.sys

6.1.7600.21380

3,807,064

23-Nov-2012

04:41

IA-64

Fwpkclnt.sys

6.1.7601.22172

483,160

23-Nov-2012

05:07

IA-64

Tcpip.sys

6.1.7601.22172

3,819,864

23-Nov-2012

05:07

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

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

Additional files for all supported x86-based versions of Windows 7

File name

Update.mum

File version

Not Applicable

File size

2,773

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

X86_26044e90acbdfede455298ffd1305ce4_31bf3856ad364e35_6.1.7600.21380_none_175459c5cfe74d05.manifest

File version

Not Applicable

File size

702

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

X86_dc0985d72dd1ad04391363e46c31c8d8_31bf3856ad364e35_6.1.7601.22172_none_a8cfd956430464d8.manifest

File version

Not Applicable

File size

1,054

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

X86_microsoft-windows-netio-infrastructure_31bf3856ad364e35_6.1.7601.22172_none_58e9732a2cdfdd0a.manifest

File version

Not Applicable

File size

2,540

Date (UTC)

23-Nov-2012

Time (UTC)

06:14

Platform

Not Applicable

File name

X86_microsoft-windows-tcpip-binaries_31bf3856ad364e35_6.1.7600.21380_none_b378eb20e0dc13f8.manifest

File version

Not Applicable

File size

3,834

Date (UTC)

23-Nov-2012

Time (UTC)

05:32

Platform

Not Applicable

File name

X86_microsoft-windows-tcpip-binaries_31bf3856ad364e35_6.1.7601.22172_none_b56c18a6ddf896a1.manifest

File version

Not Applicable

File size

3,834

Date (UTC)

23-Nov-2012

Time (UTC)

06:18

Platform

Not Applicable

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

File name

Amd64_05bae63ad76921f2b189f3314c8fb93e_31bf3856ad364e35_6.1.7601.22172_none_d8c6e19b3da6f053.manifest

File version

Not Applicable

File size

1,414

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Amd64_51809ba4992bd7e1a1738fb78030c5be_31bf3856ad364e35_6.1.7600.21380_none_0bbbb2a87ea78a49.manifest

File version

Not Applicable

File size

706

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Amd64_9f9582a09accee4c4c9ed8a920bbfb5a_31bf3856ad364e35_6.1.7601.22172_none_0c661c2230e1fe66.manifest

File version

Not Applicable

File size

1,060

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Amd64_a86b74c6a499518d81a63d1e3f9d2c31_31bf3856ad364e35_6.1.7601.22172_none_a380a6c1caecad26.manifest

File version

Not Applicable

File size

712

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Amd64_microsoft-windows-netio-infrastructure_31bf3856ad364e35_6.1.7601.22172_none_b5080eade53d4e40.manifest

File version

Not Applicable

File size

2,542

Date (UTC)

23-Nov-2012

Time (UTC)

07:05

Platform

Not Applicable

File name

Amd64_microsoft-windows-tcpip-binaries_31bf3856ad364e35_6.1.7600.21380_none_0f9786a49939852e.manifest

File version

Not Applicable

File size

3,838

Date (UTC)

23-Nov-2012

Time (UTC)

06:42

Platform

Not Applicable

File name

Amd64_microsoft-windows-tcpip-binaries_31bf3856ad364e35_6.1.7601.22172_none_118ab42a965607d7.manifest

File version

Not Applicable

File size

3,838

Date (UTC)

23-Nov-2012

Time (UTC)

07:12

Platform

Not Applicable

File name

Update.mum

File version

Not Applicable

File size

4,059

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Wow64_microsoft-windows-netio-infrastructure_31bf3856ad364e35_6.1.7601.22172_none_bf5cb900199e103b.manifest

File version

Not Applicable

File size

1,166

Date (UTC)

23-Nov-2012

Time (UTC)

06:00

Platform

Not Applicable

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

File name

Ia64_6a8bd2a03be0c1be7ad3bca7885faa43_31bf3856ad364e35_6.1.7600.21380_none_b6c1f292d6599d54.manifest

File version

Not Applicable

File size

704

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Ia64_ef59e55f05cc0090f37e6d3f55f56dda_31bf3856ad364e35_6.1.7601.22172_none_6a9526be54af28da.manifest

File version

Not Applicable

File size

1,411

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Ia64_microsoft-windows-netio-infrastructure_31bf3856ad364e35_6.1.7601.22172_none_58eb17202cdde606.manifest

File version

Not Applicable

File size

2,541

Date (UTC)

23-Nov-2012

Time (UTC)

06:55

Platform

Not Applicable

File name

Ia64_microsoft-windows-tcpip-binaries_31bf3856ad364e35_6.1.7600.21380_none_b37a8f16e0da1cf4.manifest

File version

Not Applicable

File size

3,836

Date (UTC)

23-Nov-2012

Time (UTC)

06:34

Platform

Not Applicable

File name

Ia64_microsoft-windows-tcpip-binaries_31bf3856ad364e35_6.1.7601.22172_none_b56dbc9cddf69f9d.manifest

File version

Not Applicable

File size

3,836

Date (UTC)

23-Nov-2012

Time (UTC)

06:59

Platform

Not Applicable

File name

Update.mum

File version

Not Applicable

File size

1,947

Date (UTC)

23-Nov-2012

Time (UTC)

13:28

Platform

Not Applicable

File name

Wow64_microsoft-windows-netio-infrastructure_31bf3856ad364e35_6.1.7601.22172_none_bf5cb900199e103b.manifest

File version

Not Applicable

File size

1,166

Date (UTC)

23-Nov-2012

Time (UTC)

06:00

Platform

Not Applicable

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