According to Washington Post, both National Security Agency (NSA) Information Assurance Directorate and The U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) reviewed and tested the Windows Vista Security Guide by running the operating system under attack, and provided comments that were incorporated in the published version.
From the download page of Windows Vista Security Guide:
The Windows Vista Security Guide solution accelerator recommends the Enterprise Client (EC) configuration for organizations of all types. Only in extreme security situations does the guide recommend the Specialized Security – Limited Functionality (SSLF) configuration, which considerably limits client computer functionality. The Solution Accelerator includes recommendations about how to use new and enhanced security technologies in Windows Vista to better defend the client computers in your organization against malware. The guide also provides recommendations and best practices on how to use encryption and access control technologies in Windows Vista to protect corporate data. Application compatibility testing recommendations are included. This Solution Accelerator includes several files, such as the Windows Vista Security Guide.doc, the detailed Appendix A of the Windows Vista Security Guide.doc, the Windows Vista Security Guide Settings.xls, and the GPOAccelerator tool to help you easily implement the guidance.
Download Windows Vista Security Guide solution accelerator from Microsoft Download Center. The download consists of Windows Vista Security Guide Release Notes.rtf and Windows Vista Security Guide.msi installer. Execute the installer to install these Windows Vista security solution accelerator together with GPOAccelerator tool (requires administrative privileges or admin rights to use the tool with Group Policy Management Console – GPMC) on your computer in a location of your choice (default installation location is your Documents folder). The installation places a shortcut to the guide that opens the Windows Vista Security Guide folder.
The Windows Vista Security Guide can also be read online on Technet.