Upgrading to Ubuntu 18.04 (Bionic Beaver)
 
 Note: To upgrade your os to Bionic Beaver(18.04) you must have prior version of ubuntu 17.10 or the last long time support(LTS) version 16.04 .   error "Target configured multiple times" fixed. scroll down to see the solution.    UBUNTU 18.04 Bionic Beaver            To upgrade to the latest version you must have the root privileges or  you can use sudo command with the administrator password. For ubuntu  18.04 LTS the support will be provided till  2023 .     steps to upgrade to 18.04:-       $sudo apt update  $sudo apt upgrade    Now that you are upgraded to 18.04 you should remove the duplicate packages using following command:     -$sudo apt dist-upgrade      dist-upgrade in addition to performing the function of upgrade,    also intelligently handles changing dependencies with new versions    of packages; apt-get has a "smart" conflict resolution system, and    it will attempt to upgrade the most important packages at the...