http://archive.ubuntu.com/ubuntu/dists/oneiric/InRelease ... I resolved my issue by using the commands below for Kubuntu platform. sudo kate /etc/apt/apt.conf.d/40proxy Enter the following into your 40proxy file under Kate . Acquire::http::Proxy "http://proxy.site.com:8080"; Or if your proxy needs authentication, you can use the following export definition. Acquire::http::Proxy  "http://proxyusername:proxypassword@proxyaddress:proxyport"; You should be able to use apt-get