var
  hSCM: SC_HANDLE;
  hService: SC_HANDLE;

  gfSERVICE_NAME : string; // Имя сервиса
  gfSERVICE_DISPLAY_NAME : string; // Отображаемое имя сервиса
...
  hSCM := OpenSCManager(nil, nil, SC_MANAGER_ALL_ACCESS);
...
  hService := CreateService(
    hSCM, PChar(gfSERVICE_NAME), pChar(gfSERVICE_DISPLAY_NAME), SERVICE_ALL_ACCESS,
    SERVICE_WIN32_OWN_PROCESS or SERVICE_INTERACTIVE_PROCESS, SERVICE_AUTO_START,
    SERVICE_ERROR_NORMAL, PChar(ParamStr(0)), nil, nil, nil, nil, nil);
...

  hSCM := OpenSCManager(nil, nil, GENERIC_READ or GENERIC_EXECUTE);
...
  hService := OpenService(hSCM, PChar(gfSERVICE_NAME), SERVICE_ALL_ACCESS);
...
  fIsErr := StartService(hService, 0, pParameters);