uses WinSvc;


function TForm1.GetServiceStatus(const ServiceName: string): DWORD;
var
  schService, schSCManager: DWORD;
  ServiceStatus: TServiceStatus;
begin
  schSCManager := OpenSCManager(nil, nil, SC_MANAGER_CONNECT);
  if schSCManager = 0 then RaiseLastWin32Error;
  try
    schService := OpenService(schSCManager, PChar(ServiceName),
      SERVICE_QUERY_STATUS or SERVICE_QUERY_CONFIG);
    if schService = 0 then RaiseLastWin32Error;
     try
      if not QueryServiceStatus(schService, ServiceStatus) then
        RaiseLastWin32Error;

      Result := ServiceStatus.dwCurrentState;
    finally
      CloseServiceHandle(schService);
    end;
  finally
    CloseServiceHandle(schSCManager);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  case GetServiceStatus('Messenger') of
    SERVICE_STOPPED, SERVICE_STOP_PENDING:
      begin
        Caption := 'It''s Stoped';
      end;

    SERVICE_START_PENDING, SERVICE_CONTINUE_PENDING, SERVICE_RUNNING:
      begin
        Caption := 'It''s Running';
      end;

    SERVICE_PAUSE_PENDING, SERVICE_PAUSED:
      begin
        Caption := 'It''s Paused';
      end;
  end;
end;

have a nice day :D