Saber se o Windows é 32 ou 64 Bits

[Jhonas]

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
function IsWindows64: Boolean;
type
  TIsWow64Process = function(AHandle:THandle; var AIsWow64: BOOL): BOOL; stdcall;
var
  vKernel32Handle: DWORD;
  vIsWow64Process: TIsWow64Process;
  vIsWow64: BOOL;
begin

  Result := False;

  vKernel32Handle := LoadLibrary('kernel32.dll');
  if (vKernel32Handle = 0) then Exit;

  try

    @vIsWow64Process := GetProcAddress(vKernel32Handle, 'IsWow64Process');
    if not Assigned(vIsWow64Process) then Exit;

    vIsWow64 := False;
    if (vIsWow64Process(GetCurrentProcess, vIsWow64)) then
      Result := vIsWow64;

  finally
    FreeLibrary(vKernel32Handle);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
   if IsWindows64 = true then
      showmessage('O sistema windows é 64 Bits')
   else
      showmessage('O sistema windows é 32 Bits')
end;

end.