sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup #kopia zapasowa
sudo rm /etc/apt/sources.list #usunięcie aktualnej wersji
sudo sh -c 'echo "# Ubuntu supported packages
deb http://archive.ubuntu.com/ubuntu/ lucid main restricted multiverse universe
deb http://archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ lucid-updates main restricted multiverse universe
deb http://security.ubuntu.com/ubuntu lucid-security main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu lucid-proposed main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ lucid main restricted multiverse universe
deb-src http://archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ lucid-updates main restricted multiverse universe
deb-src http://security.ubuntu.com/ubuntu lucid-security main restricted universe multiverse
deb-src http://security.ubuntu.com/ubuntu lucid-proposed main restricted universe multiverse
#Canonical Commercial Repository
deb http://archive.canonical.com/ubuntu lucid partner
deb http://archive.canonical.com/ubuntu lucid-backports partner
deb http://archive.canonical.com/ubuntu lucid-updates partner
deb http://archive.canonical.com/ubuntu lucid-security partner
deb http://archive.canonical.com/ubuntu lucid-proposed partner
deb-src http://archive.canonical.com/ubuntu lucid partner
deb-src http://archive.canonical.com/ubuntu lucid-backports partner
deb-src http://archive.canonical.com/ubuntu lucid-updates partner
deb-src http://archive.canonical.com/ubuntu lucid-security partner
deb-src http://archive.canonical.com/ubuntu lucid-proposed partner
#medibuntu
deb http://packages.medibuntu.org/ lucid free non-free
deb-src http://packages.medibuntu.org/ lucid free non-free
#PlayOnLinux
deb http://deb.playonlinux.com/ lucid main
#Skype
deb http://download.skype.com/linux/repos/debian/ stable non-free " >> /etc/apt/sources.list'
sudo add-apt-repository ppa:alexey-smirnov/deadbeef
# Autoupdate
sudo apt-get update
sudo apt-get dist-upgrade
Przedstawiam do weryfikacji to co wypisałem w pliku sh

Oczywiście lista repozytoriów to sprawa indywidualna dla każdego usera
