Assuming that your system is Ubuntu alike … first “completely remove” / “purge” (i.e. “remove with any associated configuration files”) all ROOT 5 related packages, i.e. execute “sudo apt-get purge root-system* root-plugin* libroot*” (afterwards check that the “/usr/lib/i386-linux-gnu/root5.34” and the “/usr/lib/x86_64-linux-gnu/root5.34” subdirectories disappeared completely and make sure that " /usr/lib/x86_64-linux-gnu/" doesn’t contain any “libCint*”, “libCore*” and so on).