我怎样才能解决那些失败的问题？

Question

W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/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-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/multiverse/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-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/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-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/universe/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-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/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-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/multiverse/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-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/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 cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/universe/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/gwibber-daily/ppa/ubuntu/dists/quantal/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/quantal/main/binary-i386/Packages  404  Not Found

E: Some index files failed to download. They have been ignored, or old ones used instead.

Answer 1

用sources.list编辑sudo nano /etc/apt/sources.list

删除带有安装CD的行(可能是第一行或第二行，以"deb cdrom：“开头)，行中包含PPA。如果没有这一行，请查看/etc/apt/sources.list.d/并使用gwibber的PPA删除文件。