November 23rd, 2004
DirectX 9.1 or newer (must include “dxerr9.lib”)
http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/directx9_c/directx/intro/program/debugging/dxgeterrordescription9.asp
DirectX 8.1 (must include “dxerr8.lib”)
http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/dx81_c/directx_cpp/Intro/ProgramCPP/Debugging/dxgeterrordescription8.asp
you also can use AMGetErrorText (Quartz.lib).
http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/directx9_c/directx/htm/amgeterrortext.asp