Support for Windows Vista without any service packs installed ended on April 13, 2010. To continue receiving security updates for Windows, make sure you're running Windows Vista with Service Pack 2 (SP2). For more information, refer to this Microsoft web page: Support is ending for some versions of Windows
Consider the following scenario:
You have a Windows Vista-based computer.
The computer uses two or more DirectX-compatible graphics processing units (GPUs) in a linked configuration.
You are using a DirectX 10 application and driver.
In this scenario, the computer's graphics performance indicates that only a single GPU is being used.
This problem occurs because the operating system does not forward driver-render requests to the secondary GPU.
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:
935791 How to obtain the latest Windows Vista service pack
The following files are available for download from the MicrosoftDownload Center:
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.
No prerequisites are required.
You must restart the computer after you apply this update.
Update replacement information
This update does not replace a previously released update.
The English version of this update 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.