I gave the way to check the latter above, but for the former, look at the head of /etc/apt/sources.list. The first line should be this if you have the correct image:
deb cdrom:[Lubuntu 18.10 _Cosmic Cuttlefish_ - Release amd64 (20181017.2)]/ cosmic main multiverse restricted universe -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801438 Title: "Install Lubuntu 18.10" icon on desktop results in "Execute File" window appearing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/calamares/+bug/1801438/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
