Several client computers are running Windows Vista or Windows Server 2008 in a Windows Server 2008-based domain environment.
Not all the client computers have update 2560500 installed.
You use the Server Message Block (SMB) Version 2 protocol in the network. For example, you connect some client computers to Windows Server 2008-based file servers by using the SMB Version 2 protocol.
A named pipe operation occurs on the client computers that use the SMB Version 2 protocol.
You turn on more than two client computers that do not have update 2560500 installed. Then, you try to log on to the client computers.
In this scenario, it takes longer than expected to log on to the client computers. For example, it takes more than 15 minutes to log on to the client computers.
This issue occurs because the wrong Query Information is used for the SMB Version 2 protocol on computers that do not have update 2560500 installed. Therefore, the Query Information blocks the worker threads of the SMB Version 2 protocol on the server, and every request by the SMB Version 2 protocol is delayed for one second.
After you apply the following hotfix package on a Windows Vista-based or Windows Server 2008-based computer that has the File Server role installed, the default REG_DWORD value of the SrvMaxThreadsPerQueue registry entry is changed from 10 to 20. The SrvMaxThreadsPerQueue registry entry is located under the following registry subkey:
Windows Vista and Windows Server 2008 have hardcoded SMB Version 2 protocol limits for the value of the SrvMaxThreadsPerQueue registry entry. The default value is 10. The maximum value of the SrvMaxThreadsPerQueue registry entry is 65,535.
The value of the SrvMaxThreadsPerQueue registry entry determines the maximum number of threads that the server creates to service the processor queue. When the Receive Side Scaling (RSS) feature of the network interface works as expected, the server service maintains a separate queue of client requests for each processor on the computer.
After you apply this hotfix, you can increase value of the SrvMaxThreadsPerQueue registry entry to improve the performance of the file server. You must restart the server service after you change the value of the registry entry. Run the following commands to restart the server service:
net stop server
net start server
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.
To apply this hotfix, you must be running Windows Vista Service Pack 2 (SP2) or Windows Server 2008 SP2. Additionally, you must have the File Server role installed.
For more information about how to obtain a Windows Vista service pack, click the following article number to view the article in the Microsoft Knowledge Base:
935791How to obtain the latest Windows Vista service pack
For more information about how to obtain a Windows Server 2008 service pack, click the following article number to view the article in the Microsoft Knowledge Base:
968849How to obtain the latest service pack for Windows Server 2008
To apply this hotfix, you do not have to make any changes to the registry.
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 Vista and Windows Server 2008 file information notes
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 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.
6.0.600 2. 22xxx
Windows Vista and Windows Server 2008
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 Vista and for Windows Server 2008" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important 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 Vista and of Windows Server 2008
For all supported x64-based versions of Windows Vista and of Windows Server 2008
For all supported IA-64-based versions of Windows Server 2008
To work around this issue, use one of the following methods.
Method 1 Disable the SMB Version 2 protocol on the Windows Server 2008-based file server. To do this, follow these steps:
Click Start, type regedit in the Start Search box, and then press ENTER.
Locate and then click the following registry subkey:
Windows Server 2008 Enterprise, Windows Server 2008 Enterprise without Hyper-V, Windows Server 2008 Datacenter, Windows Server 2008 Datacenter without Hyper-V, Windows Server 2008 for Itanium-Based Systems, Windows Server 2008 Foundation, Windows Server 2008 Standard, Windows Server 2008 Standard without Hyper-V, Windows Web Server 2008, Windows Vista Enterprise, Windows Vista Enterprise 64-bit Edition, Windows Vista Business, Windows Vista Business 64-bit Edition, Windows Vista Ultimate, Windows Vista Ultimate 64-bit Edition