You receive a "400 – BadRequest" error message from Internet Information Services 6.0

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SYMPTOMS

When you send a request to a Microsoft Windows Server 2003-based computer that is running Microsoft Internet Information Services (IIS) 6.0, you may receive an error message that is similar to the following:

HTTP/1.1 GET / 400 – BadRequest

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CAUSE

This issue occurs if the request headers are terminated with only the line feed (LF) delimiter or the 0x0A delimiter. By default, IIS 6.0 requires that request headers are terminated with the carriage return line feed (CRLF) delimiter or the 0x0D0A delimiter.

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RESOLUTION

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:

http://support.microsoft.com/contactus/?ws=support (http://support.microsoft.com/contactus/?ws=support)

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

No prerequisites are required.

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
--------------------------------------------------------
01-Apr-2004  00:47  5.2.3790.146      335,872  Http.sys (x86)
01-Apr-2004  00:48  5.2.3790.146      851,968  Http.sys (IA-64)

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MORE INFORMATION

The carriage return delimiter can be represented by CR or by 0xD. The line feed delimiter can be represented by LF or by 0xA. The carriage return line feed delimiter can be represented by CRLF or by 0x0D0A.

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