Instalador em delphi identificação do directX

function GetDirectXVersion( var major, minor: word ): Boolean;
var
  Reg: TRegistry;
  str: string;
  res: Boolean;
begin
  str := ´´;
  res := False;
  major := 0;
  minor := 0;
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_LOCAL_MACHINE;
    if Reg.OpenKey( ´\Software\Microsoft\DirectX´, False ) then
    begin
      res := True;
      str := Reg.ReadString( ´Version´ );
    end;
  finally
    Reg.CloseKey;
    Reg.Free;
  end;
  if res then
  begin
    Delete( str, 1, POS( ´.´, str ) );
    Major := StrToInt( Copy( str, 1, POS( ´.´, str ) - 1 ) );
    Delete( str, 1, POS( ´.´, str ) );
    Minor := StrToInt( Copy( str, 1, POS( ´.´, str ) - 1 ) );
  end;

  GetDirectXVersion := res;
end;

var
  Minor, Major: Word;
begin
  if GetDirectXVersion(Minor, Major) then
    ShowMessageFmt(Versão DirectX ¬d´, [Major])
  else
    ShowMessage(´DirectX não Instalado´);
end;