You receive a compile error in your ATL project after you install the Windows SDK 6.1 with Visual Studio 2008 Service Pack 1

Consider the following scenario. You install Microsoft Visual Studio 2008 Service Pack 1 (SP1). Or, you install some updates for Visual Studio 2008 SP1. Then, you install the Windows Software Development Kit (SDK) 6.1. In this scenario, you receive the following compiler error message in your Active Template Library (ATL) projects:

The Windows SDK for Windows Server 2008 and the .NET Framework 3.5 (Windows SDK 6.1) shares several C Runtime files with Visual Studio 2008. The Windows SDK 6.1 has the Visual Studio 2008 RTM version of these files. If you install Windows SDK 6.1 after you install Visual Studio 2008 Service Pack 1 or a later version of Visual Studio 2008, unversioned files that are shared between the Windows SDK 6.1 and Visual Studio 2008 are rolled back to the RTM version. There are incompatibilities between the Visual Studio 2008 RTM file versions and newer versions of the C Runtime files. Therefore, a compiler error can occur when these incompatible files are mixed together.

To resolve this problem, install update 974479. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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