FIX: An audio or video file does not play in Windows Media Player when you connect through a proxy server that uses an autoproxy script

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Consider the following scenario:
  • You try to play an audio or video file in Microsoft Windows Media Player.
  • The file is located on a Windows Media server.
  • You connect through a proxy server.
  • The proxy server uses an autoproxy script such as Proxy.pac or Wpad.dat.
  • The proxy autoproxy script calls the IsInNet function.
In this scenario, the audio or video file does not play.

When you use the same autoproxy script together with Internet Explorer, no problems occur.
This problem occurs because Windows Media Player incorrectly evaluates the IsInNet function. A value of "false" is always returned. This is true regardless of what is passed to the function.

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.

To resolve this problem, obtain the hotfix from the Microsoft Download Center.

Download information

The following files are available for download from the MicrosoftDownload Center:
Windows Vista, x86-based versions (all languages)
DownloadDownload the Windows6.0-KB950478-x86.msu package now.
Windows Vista, x64-based versions (all languages)
DownloadDownload the Windows6.0-KB950478-x64.msu package now.
Windows XP, 32-bit versions (all languages)
DownloadDownload the WindowsMedia11-KB950478-x86-INTL.exe package now.
Windows XP, 64-bit versions (all languages)
DownloadDownload the WindowsMedia11-KB950478-x64-INTL.exe package now.
Note This hotfix does not have an x64-based version for Windows XP. The WindowsMedia11-KB950478-x64-INTL.exe package applies the 32-bit version of this hotfix to the x64-based version of Windows XP.

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

File information

The global 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 item in Control Panel.
Windows Vista
File nameFile versionFile sizeDateTimePlatformFolder
Windows XP
File nameFile versionFile sizeDateTimePlatform
Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section.
pac autopad.dat

Article ID: 950478 - Last Review: 01/16/2015 16:16:40 - Revision: 2.0

Windows Media Player 11

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