After you install the update that is described in Microsoft Knowledge Base (KB) article 2551177 on a computer that is running Windows Vista or Windows Server 2008, network file transfer operations are slow. For example, if your user profile is stored on a remote server, you experience a delay of 20 to 40 seconds when you log on a client computer that is running Windows Vista or Windows Server 2008.
This issue may affect the performance of other SMB-based network operations, such as reading or writing multiple files.
For more information about KB 2551177, click the following article number to view the article in the Microsoft Knowledge Base:
2251177 You cannot access shared files or shared printers from a computer that is running Windows Vista or Windows Server 2008
This issue occurs because an event signal is delayed when the Redirected Drive Buffering Subsystem (RDBSS) has to delete and uninitialize the cache map. The delay occurs when RDBSS performs an uninitialize operation that is followed by a delete operation. The delete operation is called before the uninitialize operation is complete. During the logon process, many files are opened and closed. This behavior causes the delay in the logon process.
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:
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 Service Pack 2 (SP2).
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:
935791 How 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:
968849 How to obtain the latest service pack for Windows Server 2008
To apply the hotfix in this package, 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 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.
For all supported x86-based versions of Windows Server 2008 and of Windows Vista
For all supported x64-based versions of Windows Server 2008 and of Windows Vista
For all supported IA-64-based versions of Windows Server 2008
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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
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