...überprüfen ob Winsock verfügbar ist?

uses
  Winsock;

function WinsockEnabled: Boolean;
var
  wsaData: TWSAData;
begin
  Result := True;
  case Winsock.WSAStartup($0101, wsaData) of
    WSAEINVAL, WSASYSNOTREADY, WSAVERNOTSUPPORTED: Result := False;
    else
      Winsock.WSACleanup;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if WinsockEnabled then
    ShowMessage('Winsock is enabled')
  else
    ShowMessage('Winsock is disabled');
end;