Public Sub EnableDisableModems(ByVal enable As Boolean)
    'enum-ератор на основании GUID_DEVINTERFACE_MODEM

    Dim bResult As Boolean
    Dim m_ClassGUID As Guid
    Dim hDeviceInfoSet As IntPtr
    Dim wIndex As Integer
    Dim m_DeviceInfoData As SP_DEVINFO_DATA
    Dim dwRes As Integer

    'можно CLSIDFromString вместо IIDFromString -пофиг
    dwRes = IIDFromString(GUID_DEVINTERFACE_MODEM, m_ClassGUID)
    If dwRes <> S_OK Then
      'Debug.Print("IIDFromString Error " & RaiseAPIErrorByNumber(dwRes))
      Exit Sub
    End If

    'DIGCF_DEVICEINTERFACE для этого m_ClassGUID -существенно!!!
    hDeviceInfoSet = SetupDiGetClassDevs(m_ClassGUID, vbNullString, 0, _
     DIGCF_PROFILE Or DIGCF_DEVICEINTERFACE) 'DIGCF_PRESENT Or
    If hDeviceInfoSet = INVALID_HANDLE_VALUE Then
      'Debug.Print("SetupDiGetClassDevs Error " & RaiseAPIErrorByNumber(Err.LastDllError))
    Else
      'Debug.Print("hDeviceInfoSet=" & hDeviceInfoSet.ToString)

      wIndex = 0
      m_DeviceInfoData.cbSize = Marshal.SizeOf(m_DeviceInfoData)
      Do
        bResult = SetupDiEnumDeviceInfo(hDeviceInfoSet, wIndex, m_DeviceInfoData)
        If (bResult = False) And (Err.LastDllError = ERROR_NO_MORE_ITEMS) Then Exit Do

        Dim params As SP_PROPCHANGE_PARAMS
        params.ClassInstallHeader.cbSize = Marshal.SizeOf(params.ClassInstallHeader)
        params.ClassInstallHeader.InstallFunction = DIF_PROPERTYCHANGE
        params.Scope = DICS_FLAG_GLOBAL
        If enable Then
          params.StateChange = DICS_ENABLE
        Else
          params.StateChange = DICS_DISABLE
        End If

        If SetupDiSetClassInstallParams(hDeviceInfoSet, m_DeviceInfoData, params, Marshal.SizeOf(params)) Then
          'SetupDiCallClassInstaller(DIF_PROPERTYCHANGE, hDeviceInfoSet, m_DeviceInfoData)
          SetupDiChangeState(hDeviceInfoSet, m_DeviceInfoData)
        End If

        wIndex = wIndex + 1
      Loop

      SetupDiDestroyDeviceInfoList(hDeviceInfoSet)
    End If
  End Sub