uses Registry; 
 
function winvers: byte; 
var 
  reg: TRegistry; 
  build, buildx: string; 
begin 
  result := 0; 
  Reg := TRegistry.Create; 
  try 
    Reg.RootKey := HKEY_LOCAL_MACHINE; 
    if Reg.OpenKey('\SOFTWARE\Microsoft\Windows NT\CurrentVersion', False) 
      then begin 
      build := Reg.ReadString('BuildLab'); 
      buildx := Reg.ReadString('BuildLabEx'); 
      if pos('xp', build) > 0 then result := 1 
      else if pos('win7', build) > 0 then begin 
        if pos('x86', buildx) > 0 then result := 2 
        else result := 3; 
      end; 
    end; 
  finally 
    Reg.CloseKey; 
    Reg.Free; 
  end; 
end; 
 
// Beispielaufruf 
 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
  case winvers of 
    1: label2.caption := 'XP'; 
    2: label2.caption := 'W7 32Bit'; 
    3: label2.caption := 'W7 64Bit'; 
  else label2.caption := 'Kein XP und kein W7'; 
  end; 
end;