判断 Windows操作系统是32位还是64位

function IsWin64: Boolean;

var

  Kernel32Handle: THandle;

  IsWow64Process: function(Handle: Windows.THandle; var Res: Windows.BOOL): Windows.BOOL; stdcall;

  GetNativeSystemInfo: procedure(var lpSystemInfo: TSystemInfo); stdcall;

  isWoW64: Bool;

  SystemInfo: TSystemInfo;

const

  PROCESSOR_ARCHITECTURE_AMD64 = ;

  PROCESSOR_ARCHITECTURE_IA64 = ;

begin

  Kernel32Handle := GetModuleHandle('KERNEL32.DLL');

  if Kernel32Handle =  then

    Kernel32Handle := LoadLibrary('KERNEL32.DLL');

  if Kernel32Handle <>  then

  begin

    IsWOW64Process := GetProcAddress(Kernel32Handle,'IsWow64Process');

    GetNativeSystemInfo := GetProcAddress(Kernel32Handle,'GetNativeSystemInfo');

    if Assigned(IsWow64Process) then

    begin

      IsWow64Process(GetCurrentProcess,isWoW64);

      Result := isWoW64 and Assigned(GetNativeSystemInfo);

      if Result then

      begin

        GetNativeSystemInfo(SystemInfo);

        Result := (SystemInfo.wProcessorArchitecture = PROCESSOR_ARCHITECTURE_AMD64) or

                  (SystemInfo.wProcessorArchitecture = PROCESSOR_ARCHITECTURE_IA64);

      end;

    end

    else Result := False;

  end

  else Result := False;

end;

http://blog.csdn.net/suiyunonghen/article/details/4870219

网上这样的代码和讨论很多，特别是IsWow64Process函数的使用。

忽然想：只有32位的EXE在运行时才需要判断OS是32还是64bit？

如果EXE本身是64bit的，那么运行时根本不用判断了，OS必定是64位的，否则根本不能运行的。

所以，本人感觉网上很多讨论是否有点多余？