- Microsoft Outlook or Windows Mail
- Web browsers, such as Windows Internet Explorer 7
- Remote Desktop Connection (RDC)
- File sharing programs
This issue may occur if the firewall device has a problem with handling the Receive Window Auto-Tuning feature in Windows Vista. This article helps you work around this problem.
Method 1. Disable auto-tuning and determine whether Windows scaling is handled correctly by the firewall deviceTo have us disable auto-tuning for you, go to the "Fix it for me" section. If you would rather disable auto-tuning yourself, go to the "Let me fix it myself" section.
Fix it for meTo disable auto-tuning automatically, click the Fix this problem link. Then, click Run in the File Download dialog box, and follow the steps in this wizard.
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 myselfTo disable auto-tuning, follow these steps:
- Click Start, click All Programs, and then click Accessories.
- Right-click Command Prompt, and then click Run as Administrator. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
- At the command prompt, type the following command, and then press ENTER: netsh interface tcp set global autotuninglevel=disabledThis command disables the Receive Window Auto-Tuning feature.
- Close the Command Prompt window.
- Restart the computer.
Did this fix the problem?
- Try to make a non-HTTP network connection. That is, use the program that was affected by the problem.
- If the problem is fixed, contact the manufacturer of the firewall device for steps to resolve the issue. If the problem is not fixed, you can contact support.
- You can keep auto-tuning disabled until the problem is fixed. When you are ready to enable auto-tuning, click Start, click All Programs, click Accessories, and then click Command Prompt.
- At the command prompt, type the following command, and then press ENTER: netsh interface tcp set global autotuninglevel=normalThis command enables Receive Window Auto-Tuning again so that you can take advantage of the increase in network throughput performance that this option provides.
"Fix it for me" blog, or send us an
For information about how to contact the manufacturer of the firewall device, visit the following Microsoft Web site: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
Method 2. Run the Internet Connectivity Evaluation ToolThe Internet Connectivity Evaluation Tool checks your Internet router to see whether it supports certain technologies. The tool is intended to be run from a home network behind a home Internet (NAT) router. Running this tool from behind a corporate firewall or on operating systems other than those specified in the "Applies to" section will not produce accurate results. This tool requires administrator credentials to run.
- Linksys RV series (RV042, RV081, RV-16)
- NetApp Cache Appliances NC 6.0.2 or an earlier version
The TCP splicing feature may not work together with the Window Scaling feature in Windows Vista. By default, the TCP splicing feature is enabled on NetApp Cache Appliances NC 6.0.2 or on an earlier version.
- Cisco PIX 6.1(5), Cisco PIX 6.2(3), and Cisco PIX 6.3(1)
These devices do not support the Window Scaling feature in Windows Vista.
- Cisco IOS Software Release
Cisco IOS Software Release 12.3(15) and later versions of this software support the Window Scaling feature in Windows Vista.
The Window Scaling feature in Windows Vista may not work if you enable either of the following features on a Sonicwall firewall device:
- Strict TCP Enforcement Option
- Enforce strict TCP compliance with RFC 793 and RFC 1122
- Checkpoint NG R55
To work around this issue, disable the Sequence Verifier Enforcement feature.
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.