Symptom(s):

A number of symptoms are caused by the same issue. Symptoms might include any of the following.

• Network connections are slow or time out with error messages.
• Messages might include text such as "The connection to the server was interrupted" "Page cannot be displayed."
• Downloading mail from an Internet Service Provider (ISP) takes longer than expected.

Cause:
By default, Windows Vista uses TCP autotuning to control TCP Receive Window size. If your router or firewall does not support TCP Window Scale option then slow or dropped connections might occur.

Solution:

There is no Intel network connection driver or software setting to control the TCP Receive Scale option. This option is controlled by the network stack of Windows Vista*. To disable the the TCP Receive Window Autotuning level in Windows Vista, follow these steps:

1. Open a command prompt window. (Click Start, click All Programs, click Accessories, and click Command Prompt.)
2. Type the following command and press Enter:
        netsh interface tcp set global autotuninglevel=disabled

If you upgrade your firewall or router and want to set this feature to its default value, follow these steps:

1. Open a command prompt window. (Click Start, click All Programs, click Accessories, and click Command Prompt.)
2. Type the following command and press Enter:
        netsh interface tcp set global autotuninglevel=normal

Related Documents:
TCP Receive Window Auto-Tuning Explained*
Slow Internet Connections or Error message: "Page cannot be displayed"*
Slow E-Mail Downloads or Error Message in Outlook*
Network connectivity may fail when you try to use Windows Vista behind a firewall device*

Operating System:

Windows Vista 64*, Windows Vista Starter, 32-bit version*, Windows Vista Home Basic, 32-bit version*, Windows Vista Home Premium, 32-bit version*, Windows Vista Business, 32-bit version*, Windows Vista Enterprise, 32-bit version*, Windows Vista Ultimate, 32-bit version*, Windows Vista Home Basic, 64-bit version*, Windows Vista Home Premium, 64-bit version*, Windows Vista Business, 64-bit version*, Windows Vista Enterprise, 64-bit version*, Windows Vista Ultimate, 64-bit version*, Windows Vista *, Windows Vista 32*

This applies to:

IntelŽ PRO/100 M Desktop Adapter IntelŽ PRO/100 S Desktop Adapter IntelŽ PRO/100 S Dual Port Server Adapter IntelŽ PRO/100 S Server Adapter IntelŽ PRO/100 VE Desktop Adapter IntelŽ PRO/100 VE Network Connection IntelŽ PRO/100 VM Network Connection IntelŽ PRO/100+ Adapter IntelŽ PRO/100+ Management Adapter IntelŽ PRO/100+ Server Adapter IntelŽ PRO/1000 GT Desktop Adapter IntelŽ PRO/1000 MF Dual Port Server Adapter IntelŽ PRO/1000 MF Server Adapter IntelŽ PRO/1000 MF Server Adapter (LX) IntelŽ PRO/1000 MT Desktop Adapter IntelŽ PRO/1000 MT Dual Port Server Adapter IntelŽ PRO/1000 MT Server Adapter IntelŽ PRO/1000 PF Dual Port Server Adapter IntelŽ PRO/1000 PF Server Adapter IntelŽ PRO/1000 PT Desktop Adapter IntelŽ PRO/1000 PT Dual Port Server Adapter IntelŽ PRO/1000 PT Server Adapter IntelŽ PRO/1000 T Desktop Adapter IntelŽ PRO/100B Adapter