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:
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 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.
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.
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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 1.21xxx | Windows 7 and Windows Server 2008 R2 | SP1 | LDR |
- GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.
- 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 |
|---|
| Fwpkclnt.sys | 6.1.7600.21166 | 187,248 | 09-Mar-2012 | 14:14 |
| Tcpip.sys | 6.1.7600.21166 | 1,303,408 | 09-Mar-2012 | 14:15 |
| Fwpkclnt.sys | 6.1.7601.21939 | 187,760 | 09-Mar-2012 | 13:57 |
| Tcpip.sys | 6.1.7601.21939 | 1,306,480 | 09-Mar-2012 | 13:58 |
For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
| File name | File version | File size | Date | Time |
|---|
| Fwpkclnt.sys | 6.1.7600.21166 | 288,112 | 09-Mar-2012 | 15:09 |
| Tcpip.sys | 6.1.7600.21166 | 1,879,920 | 09-Mar-2012 | 15:09 |
| Fwpkclnt.sys | 6.1.7601.21939 | 288,624 | 09-Mar-2012 | 15:37 |
| Tcpip.sys | 6.1.7601.21939 | 1,902,960 | 09-Mar-2012 | 15:37 |
For all supported IA-64-based versions of Windows Server 2008 R2
| File name | File version | File size | Date | Time |
|---|
| Fwpkclnt.sys | 6.1.7600.21166 | 482,672 | 09-Mar-2012 | 14:07 |
| Tcpip.sys | 6.1.7600.21166 | 3,807,600 | 09-Mar-2012 | 14:07 |
| Fwpkclnt.sys | 6.1.7601.21939 | 483,184 | 09-Mar-2012 | 13:57 |
| Tcpip.sys | 6.1.7601.21939 | 3,814,768 | 09-Mar-2012 | 13:58 |
WORKAROUND
To work around the issue, use one of the following methods:
- If the network driver supports the Large Send Offload (LSO) feature, disable the feature on the network adapter.
To disable the Large Send Offload feature, follow these steps:- Open Control Panel, and then click Network and Internet.
- Click Network and Sharing Center.
- In the left panel, click Change adapter settings.
- Right-click the appropriate Local Area Connection, and then click Properties.
- Click Configure.
- On the Advanced�tab, select the Large Send Offload option in the�Property list, and then select Disabled in the Value field.
Note Disable all separate options for the Large Send Offload feature for both IPv4 and IPv6. - Change the connection security rule to encrypt traffic on all ports between the two IP addresses.