From https://www.ubuntu.com/download/desktop : "The download of Ubuntu 17.10 is currently discouraged due to an issue on certain Lenovo laptops. Once fixed this download will be enabled again." Here's the bug report: https://bugs.launchpad.net/ubuntu/ source/linux/ bug/1734147 And further information: https://www.theregister.co.uk/2017/12/21/ubuntu_lenovo_bios/