"WinHTTP Assertion failed" error message when you run a program that uses WinHTTP services in Windows XP or in Windows 2000

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Article ID: 834692 - View products that this article applies to.
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SYMPTOMS

When you run a program that uses Microsoft Windows HTTP Services (WinHTTP) on a Microsoft Windows XP-based or Windows 2000-based computer, you may receive the following access violation error message:
WinHttp Assertion failed: error == ERROR_SUCCESS && fsm.m_dwBytesRead - fsm.m_nBytesCopied == dwChunkBytesRead

RESOLUTION

Windows XP service pack information

To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack

Windows XP 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
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 do not have to 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 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.
Windows XP, 64-bit editions
   Date         Time   Version        Size     File name    Platform
   -----------------------------------------------------------------
   23-Feb-2004  10:49  5.1.2600.1349  953,344  Winhttp.dll  IA-64

Windows XP, 32-bit editions
   Date         Time   Version        Size     File name    Platform
   -----------------------------------------------------------------
   23-Feb-2004  10:49  5.1.2600.1349  313,344  Winhttp.dll  x86

Windows 2000 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
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 do not have to 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
   -------------------------------------------------------
   13-Jan-2004  08:32  5.1.2600.1330  312,832  Winhttp.dll

STATUS

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

Windows XP

This problem was first corrected in Windows XP Service Pack 2.

MORE INFORMATION

For additional information about how hotfix packages are named, click the following article number to view the article in the Microsoft Knowledge Base:
816915 New file naming schema for Microsoft Windows software update packages
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

Properties

Article ID: 834692 - Last Review: August 29, 2007 - Revision: 2.1
APPLIES TO
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Professional Edition
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows XP Professional
  • Microsoft Windows XP Home Edition
Keywords: 
kbautohotfix kbhotfixserver kbqfe kbhotfixserver kbqfe kbqfe kbwinxpsp2fix kbbug kbfix kbwin2000presp5fix KB834692

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