As examples of using my ‘isorespin.sh‘ script I’ve created various ISOs including those suitable for Intel Atom and Intel Apollo Lake devices.
Once you have downloaded your ISO it is necessary to write it to an USB to create an installation USB often known as a LiveUSB as not only can you install Ubuntu from it but you can also run Ubuntu for diagnostic, testing and fixing and existing installation.
There are several ways to write the ISO to USB however I recommend using Rufus on Windows:
or dd on Linux:
dd if=ubuntu-18.04-desktop-amd64.iso of=/dev/sdX bs=4M
where ‘ubuntu-18.04-desktop-amd64.iso’ is your ISO and ‘sdX’ is the USB drive using ‘ls -l /dev/disk/by-id/usb* | head -1 | sed “s?.*/??”‘ to determine this.
Please donate if you find these ISOs useful.