W: Failed to fetch cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1)/dists/saucy/restricted/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs E: Some index files failed to download. They have been ignored, or old ones used instead.
I am new to ubuntu so I dont know how to solve this error. This is shown at the end after executing 'sudo apt-get update' command. I think this is preventing me from installing new apps like