After installing Ubuntu 12.04, I tried to update, but I got the following:
student@student-25:~$ sudo apt-get update && sudo apt-get upgrade Ign cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423) precise InRelease Ign cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423) precise/main TranslationIndex Ign cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423) precise/restricted TranslationIndex Ign cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release i38Translation-en Ign http://extras.ubuntu.com precise InRelease Err http://extras.ubuntu.com precise Release.gpg Unable to connect to extras.ubuntu.com:http:
Help?