check if is windows 64bit

IsWin64.pas

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 = 9;
 PROCESSOR_ARCHITECTURE_IA64  = 6;
begin
 Kernel32Handle := GetModuleHandle('KERNEL32.DLL');
 if Kernel32Handle = 0 then
   Kernel32Handle := LoadLibrary('KERNEL32.DLL');
 if Kernel32Handle <> 0 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;