unit main;

interface

uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls;

type
 TForm1 = class(TForm)
   Button1: TButton;
   Edit1: TEdit;
   Button2: TButton;
   procedure Button1Click(Sender: TObject);
   procedure Button2Click(Sender: TObject);
 private
   procedure ShowWow64 (ProcessHandle: THandle);
 end;

var
 Form1: TForm1;

implementation

{$R *.dfm}

type
 TIsWow64Process = function (H: THandle; Value: PBOOL): BOOL; stdcall;
var
 _IsWow64Process: TIsWow64Process;

procedure TForm1.Button1Click(Sender: TObject);
begin
 ShowWow64(GetCurrentProcess);
end;

procedure TForm1.Button2Click(Sender: TObject);
var
 Pid: Cardinal;
 ProcessHandle: THandle;
begin
 Pid := StrToIntDef(Edit1.Text, GetCurrentProcessId);
 ProcessHandle := OpenProcess(PROCESS_QUERY_INFORMATION, false, Pid);
 if ProcessHandle <> 0 then
   try
     ShowWow64(ProcessHandle);
   finally
     CloseHandle(ProcessHandle);
   end
 else
   ShowMessageFmt('Can''t open process %.8x', [Pid]);
end;

procedure TForm1.ShowWow64(ProcessHandle: THandle);
const
 ProcessInfos: array[Boolean] of string = (
   'not running under Wow64', 'running under Wow64'
 );
var
 RunWow64: BOOL;
begin
 @_IsWow64Process := GetProcAddress(GetModuleHandle('kernel32'), 'IsWow64Process');
 if Assigned(_IsWow64Process) then
   if _IsWow64Process(ProcessHandle, @RunWow64) then
     ShowMessageFmt('process is %s', [ProcessInfos[RunWow64]])
   else
     RaiseLastOsError
 else
   ShowMessage('IsWow64Process is not implemented');
end;

end.