A Windows Server 2003-based computer responds slowly to RDP connections or to SMB connections that are made from a Windows Vista-based computer

Consider the following scenario:

• You install Windows Server 2003 Service Pack 2 (SP2) or Windows Server 2003 Scalable Networking Pack (SNP) on a Windows Server 2003-based computer.
• The EnableTCPA registry entry is set to "1" under the following registry subkey:
  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
• Network Driver Interface Specification (NDIS) 5.2 miniports are installed on the computer.
• Firewalls and IPsec are not enabled in Windows Server 2003.

In this scenario, the Windows Server 2003-based computer responds slowly to Remote Desktop Protocol (RDP) connections or to server message block (SMB) connections that are made from a Windows Vista-based computer. For example, when you copy files from a Windows Vista-based computer to a Windows Server 2003-based computer, the copying speed is very slow.

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 this specific problem. 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.

Prerequisites

To apply this hotfix, you must have Windows Server 2003 Service Pack 1 or Windows Server 2003 Service Pack 2 installed on the computer. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

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 Server 2003 with Service Pack 1, x86-based versions

Windows Server 2003 with Service Pack 2, x86-based versions

Windows Server 2003 with Service Pack 1, Itanium-based versions

Windows Server 2003 with Service Pack 2, Itanium-based versions

Windows Server 2003 with Service Pack 1, x64-based versions

Windows Server 2003 with Service Pack 2, x64-based versions

Use one of the following workarounds, as appropriate for your situation.

Workaround 1

Disable the TCP autotuning feature on the Windows Vista-based computer. To have us disable autotuning for you, go to the “Fix it for me” section. If you would rather disable autotuning yourself, go to the “Let me fix it myself” section.

Fix it for me

To disable autotuning automatically, click the Fix this problem link. Then click Run in the File Download dialog box, and follow the steps in this wizard.

Fix this problem
Microsoft Fix it 50056

Note this wizard may be in English only; however, the automatic fix also works for other language versions of Windows.

Note If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD, and then you can run it on the computer that has the problem.

Now go to the "Did this fix the problem?" section.

Let me fix it myself

To fix it yourself, follow these steps:

1. Log on to the computer as a user who has administrative credentials.
2. Click Start, type the following in the Start Search box, and then press ENTER:
   runas /user:Local_Computer_Name\administrator cmd
3. When you are prompted for the administrator account password, type the correct password, and then press ENTER.
4. At the command prompt, type the following command, and then press ENTER:
   netsh interface tcp set global autotuninglevel=disabled
5. Exit the Command Prompt window.
6. Restart the computer.

Now go to the "Did this fix the problem?" section.

Did this fix the problem?

Check whether the problem is fixed. If the problem is fixed, you are finished with this article. If the problem is not fixed, you can contact support (http://support.microsoft.com/contactus) .

Workaround 2

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: Set the EnableTCPA registry entry to "0" on the Windows Server 2003-based computer. To do this, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate the EnableTCPA registry entry under the following registry subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
3. Right-click EnableTCPA, and then click Modify.
4. In the Value data box, type 0, and then click OK.
5. Exit Registry Editor.

Workaround 3

Enable firewalls or IPsec on the network interface of the Windows Server 2003-based computer.

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: