You receive Stop error code 0x00000019 or Stop error code 0x00000050 in the Tcpip.sys file on a Windows 2000 Server-based computer


You receive Stop error 0x19 or Stop error 0x50 on a blue screen. The error occurs in the Tcpip.sys file on a Microsoft Windows 2000 Server-based computer. The error may occur more frequently on computers that are running Microsoft Exchange Server.


This problem occurs because the TCP/IP stack tries to free a buffer that the stack did not allocate. In this scenario, the data pool header is corrupted, and the computer stops unexpectedly. This error occurs only if you use Internet Protocol security (IPsec) in your network environment.


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.

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, submit a request to 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.


You must be running Windows 2000 Server Service Pack 3 to apply this hotfix.

Restart requirement

You must restart your 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 tool in Control Panel.
   Date         Time   Version            Size    File name
19-Jun-2003 20:05 5.0.2195.6687 120,240 Afd.sys
19-Jun-2003 20:05 5.0.2195.6602 108,816 Msafd.dll
07-Oct-2004 08:29 5.0.2195.6983 318,928 Tcpip.sys
19-Jun-2003 20:05 5.0.2195.6655 16,240 Tdi.sys
19-Jun-2003 20:05 5.0.2195.6601 17,680 Wshtcpip.dll


Important These steps may increase your security risk. These steps may also make your computer or your network more vulnerable to attack by malicious users or by malicious software such as viruses. We recommend the process that this article describes to enable programs to operate as they are designed to, or to implement specific program capabilities. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this process in your particular environment. If you choose to implement this process, take any appropriate additional steps to help protect your system. We recommend that you use this process only if you really require this process.

To work around this problem until you can apply this hotfix, temporarily turn off IPsec in your network environment. To do this, follow these steps:
  1. Click Start, point to Settings, and then click Network and Dial-up Connections.
  2. Right-click your local area connection, and then click Properties.
  3. Double-click the Internet Protocol (TCP/IP) component, click Advanced, and then click the Options tab.
  4. Click IP security, and then click Properties.
  5. Click Do not use IPSEC, and then click OK four times to close the local area connection properties.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For additional information, 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

Article ID: 883516 - Last Review: Jan 13, 2012 - Revision: 1

Microsoft Windows 2000 Server