Click Upgrade and follow the on-screen instructions.If you are using Ubuntu 16.10 Server, follow below instructions to upgrade to Ubuntu 17.04.
To upgrade to Ubuntu 17.04 from the terminal (especially on servers), install the update-manager-core package if it is not already installed.
Wait for the upgrade process to complete, then reboot your machine, then login into Ubuntu 17.04.
Done The following packages will be upgraded: accountsservice apport aptitude autofs autofs5 base-files bash-completion bc bsdutils dmidecode dmsetup dosfstools efibootmgr grub-common grub-efi grub-efi-amd64 grub-efi-amd64-bin grub2-common ifupdown iproute iptables isc-dhcp-client isc-dhcp-common landscape-common language-pack-en language-pack-en-base libaccountsservice0 libasn1-8-heimdal libavahi-client3 libavahi-common-data ...
After this operation, 86.0 k B of additional disk space will be used. Extracting templates from packages: 100% Preconfiguring packages ... Installing new version of config file /etc/issue ...
option will make Ubuntu update manager check if a development release is available.
You should be notified that software is up-to-date and Ubuntu 16.10 is now available. We will see how to upgrade using the graphical update manager and how to upgrade using terminal commands. Once the upgrade is complete, restart your computer.First, fire up a terminal window and run the following command to update all software. The Ubuntu operating system's next Long Term Support release, version 16.04 (Xenial Xerus), is due to be released on April 21, 2016.Although it hasn't yet been released at the time of this writing, it's already possible to upgrade a 15.10 system to the development version of 16.04.Ubuntu 16.10, codenamed Yakkety Yak, was released on October 13, 2016.