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When you copy large files between two Windows Vista or Windows Server 2008-based computers, the copy speed may be very slow. This problem occurs even when you are working in a high bandwidth WAN network environment.
Note When you copy files between two Windows Vista or Windows Server 2008-based computers, the Server Message Block (SMB) 2.0 protocol is used.
This problem occurs because the network throttling mechanism of SMB 2.0 reduces the number of Input/Output requests that are sent over the network. Therefore, the network performance decreases.
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 Web site:
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.
Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the “Hotfix Request” page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.
To apply this hotfix on Windows Vista-based computer, you must have Windows Vista SP1 installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
935791 How to obtain the latest Windows Vista service pack
No prerequisites are required for Windows Server 2008-based computers.
You must restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace any other hotfixes.
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows Vista and Windows Server 2008 file information notes
The MANIFEST files (.manifest) and MUM files (.mum) installed for each environment are listed separately. 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 (attributes not listed) are signed with a Microsoft digital signature.
For all supported x86-based versions of Windows Server 2008 and Windows Vista
For all supported x64-based versions of Windows Server 2008 and Windows Vista
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
948066 How to use the throttling mechanism to control network performance in Windows Vista
For more information about the SMB 2.0 protocol, visit the following Web site:
Windows Vista Home Basic, Windows Vista Home Premium, Windows Vista Enterprise, Windows Vista Business, Windows Vista Ultimate, Windows Vista Business 64-bit Edition, Windows Vista Enterprise 64-bit Edition, Windows Vista Home Basic 64-bit Edition, Windows Vista Home Premium 64-bit Edition, Windows Vista Ultimate 64-bit Edition, Windows Server 2008 Standard, Windows Server 2008 Enterprise, Windows Server 2008 Datacenter, Windows Server 2008 Standard without Hyper-V, Windows Server 2008 Enterprise without Hyper-V, Windows Server 2008 Datacenter without Hyper-V