uninstall FF, reinstall.. no joy uninstall TB, reinstall.. no joy I have a clean version of win10 on another volume and both apps work fine. However in the upgraded win7 volume nither Firefox or Thunderbird can reach out.. Oh, IE cant get out of the box either.

Just Edge and Chrome are actually working as expected. Thunderbird ver 38.1.0 Firefox ver 39.0 both are fresh downloads/reinstalls and the TB install did not offer up that new calendar function that occurred on the clean win10 install.