Installing the Windows SDK to a custom location may result in unreadable docs and some tools fail.

Installing Windows Software Development Kit (SDK) for Windows Server 2008 and .NET Framework 3.5 to a custom location can potentially result in unreadable docs and may also cause some tools to fail. This is because, when the When the Windows SDK is installed to a custom location, the Microsoft Documentation Explorer and the ATL/MFC runtime are not installed by the Windows SDK. There will not issues if these components are already installed by other applications, such as Visual Studio or MSDN. If these items have not been installed previously, then documentation will not open and some tools, such as guidgen.exe, will not run

To workaround this issue:

  1. Navigate to <system drive>\Program Files\Microsoft SDKs\Windows\v6.1\Setup\sfx
  2. Double-click on dexplore.exe and vcredist.exe to install Microsoft Document Explorer and the ATL/MFC runtime.

More information in available in the Windows SDK online release notes at Release Notes.