When you are developing an application by using Microsoft Media Foundation Software Development Kit (SDK), the application cannot load the unsigned drivers list the second time or any later time that the application tries to load the list. The first time that the application tries to load the list, the list loads successfully.

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This problem occurs because the "Protected Environment Authentication and Authorization Export Driver" reports an unsigned driver only one time.

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Service pack information

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

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Hotfix information

Hotfix download information

The following files are available for download from the Microsoft Download Center.

Windows Vista for x86-based computers (all languages)

Download the Windows6.0-KB936315-x86.msu package now. (http://download.microsoft.com/download/C/3/C/C3CB2794-6ADB-4314-9402-A2D3A2516CF1/Windows6.0-KB936315-x86.msu)

Windows Vista for x64-based computers (all languages)

Download the Windows6.0-KB936315-x64.msu package now. (http://download.microsoft.com/download/C/3/C/C3CB2794-6ADB-4314-9402-A2D3A2516CF1/Windows6.0-KB936315-x64.msu)

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base: 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 for x86-based computers

File name	File version	File size	Date	Time	Platform
Ci.dll	6.0.6000.20583	618,168	21-Apr-2007	02:18	x86

Windows Vista for x64-based computers

File name	File version	File size	Date	Time	Platform
Ci.dll	6.0.6000.20583	384,696	21-Apr-2007	03:32	x64

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Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Vista Service Pack 1.

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For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

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