@echo off>nul
  if /i     %PROCESSOR_ARCHITECTURE%==x86   goto :32
  if defined PROCESSOR_ARCHITEW6432         goto :wow64
  echo Processus 64 bits natif sur une plateforme %PROCESSOR_ARCHITECTURE%
  goto :end
  :32
  if defined PROCESSOR_ARCHITEW6432 goto :wow64
  echo Processus 32 bits natif 
  goto :end
  :wow64
  echo Processus 32 bits sur une plateforme 64 bits
  :end
  @pause
  goto :eof


=============================================
NOTES
===== 
Sur une plateforme 64 bits tester avec :
C:\Windows\System32\cmd.exe 
C:\Windows\SysWOW64\cmd.exe 

HOWTO: Detect Process Bitness 
http://blogs.msdn.com/david.wang/archive/2006/03/26/HOWTO-Detect-Process-Bitness.aspx
                        == Native ==
                 	32bit 	64bit 	 WOW64
PROCESSOR_ARCHITECTURE 	x86 	AMD64 	 x86
PROCESSOR_ARCHITEW6432 	= undefined =    AMD64/IA64

WOW64 = 32bit Program on 64bit OS
Replace AMD64 with IA64 for Itaniums

WOW64
http://en.wikipedia.org/wiki/WOW64

WOW64 Implementation Details
http://msdn.microsoft.com/en-us/library/aa384274

Thread :
http://groups.google.com/group/microsoft.public.fr.windows.vista.administration/browse_frm/thread/fd11ce1132af1770/

22/09/2009
http://fspsa.free.fr/
http://fspsa.free.fr/os6432.cmd