Possible Duplicate: Duplicate sources.list entry but cannot find the duplicates? This is my source.list and seems fine to me # deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ precise main restricted # deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/restricted/binary-i386/ # deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/main/binary-i386/ # deb cdrom:[Ubuntu 11.10]/ natty main restricted # deb cdrom:[Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1)]/ natty main restricted # deb cdrom:[Ubuntu 11.10 _Oneiric Ocelot_ - Release amd64 (20111012)]/ dists/oneiric/main/binary-i386/ # deb cdrom:[Ubuntu 11.10 _Oneiric Ocelot_ - Release amd64 (20111012)]/ oneiric main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://archive.ubuntu.com/ubuntu precise main restricted ## Major bug fix updates produced after the final release of the ## distribution. ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://archive.ubuntu.com/ubuntu precise universe ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://archive.ubuntu.com/ubuntu precise multiverse ## Uncomment the following two lines to add software from the 'backports' ## repository. ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. # deb-src http://ma.archive.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. deb http://archive.canonical.com/ubuntu precise partner # deb-src http://archive.canonical.com/ubuntu natty partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. deb http://extras.ubuntu.com/ubuntu precise main deb http://archive.ubuntu.com/ubuntu precise-updates restricted main multiverse universe deb http://security.ubuntu.com/ubuntu/ precise-security restricted main multiverse universe deb http://archive.ubuntu.com/ubuntu precise main universe deb-src http://extras.ubuntu.com/ubuntu precise main # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb-src http://archive.ubuntu.com/ubuntu precise main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://archive.ubuntu.com/ubuntu precise-updates restricted deb-src http://archive.ubuntu.com/ubuntu precise-updates main restricted ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb-src http://archive.ubuntu.com/ubuntu precise universe deb-src http://archive.ubuntu.com/ubuntu precise-updates universe ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb-src http://archive.ubuntu.com/ubuntu precise multiverse deb-src http://archive.ubuntu.com/ubuntu precise-updates multiverse ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu precise-security main restricted deb-src http://archive.ubuntu.com/ubuntu precise-security main restricted deb http://archive.ubuntu.com/ubuntu precise-security universe deb-src http://archive.ubuntu.com/ubuntu precise-security universe deb http://archive.ubuntu.com/ubuntu precise-security multiverse deb-src http://archive.ubuntu.com/ubuntu precise-security multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu oneiric partner # deb-src http://archive.canonical.com/ubuntu oneiric partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. ## Major bug fix updates produced after the final release of the ## distribution. ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu precise partner # deb-src http://archive.canonical.com/ubuntu precise partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. # deb http://packages.dotdeb.org stable all # deb-src http://packages.dotdeb.org stable all # deb http://ppa.launchpad.net/bean123ch/burg/ubuntu lucid main # deb-src http://ppa.launchpad.net/bean123ch/burg/ubuntu lucid main this is the error given by apt-get update which stops at 64% reading W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise/main amd64 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise_main_binary-amd64_Packages) W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise_universe_binary-amd64_Packages) W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise/main i386 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise_main_binary-i386_Packages) W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise/universe i386 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise_universe_binary-i386_Packages) W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise-updates/restricted amd64 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_binary-amd64_Packages) W: Duplicate sources.list entry http://archive.ubuntu.com/ubuntu/ precise-updates/restricted i386 Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_binary-i386_Packages)