As root, edit /etc/apt/sources.list and change the ftp.debian.org entries to archive.debian.org, as follows: deb http://archive.debian.org/debian/ <name> main non-free contrib deb-src http://archive.debian.org/debian/ <name> main non-free contrib deb http://archive.debian.org/debian-security/ <name>/updates main non-free contrib deb-src http://archive.debian.org/debian-security/ <name>/updates main non-free contrib Note that you need to substitute <name> with the codename of the distribution you are interested in As root, run: apt-get install debian-archive-keyring and once done, again as root run: apt-get update and you’re ready for doing any installs / upgrades to your system.