I need to check if I have updates for Ubuntu. I think it is 11.05

As you can see this is what it says:

Failed to download repository information  Check your Internet connection.

Details:

W:Failed to fetch cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)/dists/precise/main/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
, W:Failed to fetch cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)/dists/precise/restricted/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
, W:Failed to fetch cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)/dists/precise/main/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
, W:Failed to fetch cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)/dists/precise/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
, W:Failed to fetch http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/precise/main/source/Sources  404  Not Found
, W:Failed to fetch http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/precise/main/binary-i386/Packages  404  Not Found
, E:Some index files failed to download. They have been ignored, or old ones used instead.