With a clean install of Visual Studio .NET and all the SDKs, I found that I had to replace #include <dxdiag.h> with #define INITGUID #include <dxdiag.h> #undef INITGUID in lldxhardware.cpp to force definitions of CLSID_DxDiagProvider and IID_IDxDiagProvider. Otherwise the build of newview et al was a piece of cake. Nice work, folks. Cheers, Scott