I don't understand, what do you mean?
For the rest, first edit your sources.list:
sudo pluma /etc/apt/sources.list
and replace its whole content with the following:
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://it.archive.ubuntu.com/ubuntu/ bionic main restricted
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://it.archive.ubuntu.com/ubuntu/ bionic-updates main restricted
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic-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 http://it.archive.ubuntu.com/ubuntu/ bionic universe
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic universe
deb http://it.archive.ubuntu.com/ubuntu/ bionic-updates universe
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic-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 http://it.archive.ubuntu.com/ubuntu/ bionic multiverse
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic multiverse
deb http://it.archive.ubuntu.com/ubuntu/ bionic-updates multiverse
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic-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://it.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://it.archive.ubuntu.com/ubuntu/ bionic-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 bionic partner
deb-src http://archive.canonical.com/ubuntu bionic partner
deb http://security.ubuntu.com/ubuntu bionic-security main restricted
deb-src http://security.ubuntu.com/ubuntu bionic-security main restricted
deb http://security.ubuntu.com/ubuntu bionic-security universe
deb-src http://security.ubuntu.com/ubuntu bionic-security universe
deb http://security.ubuntu.com/ubuntu bionic-security multiverse
deb-src http://security.ubuntu.com/ubuntu bionic-security multiverse
Then, delete the unused repos:
cd /etc/apt/sources.list.d
sudo rm bablu-boy-ubuntu-nutty_0_1-xenial* elementary-os-ubuntu-os-patches-xenial* opera-stable.list.save ubuntu-mate-dev-ubuntu-xenial-mate-xenial* elementary-os-ubuntu-daily-xenial* elementary-os-ubuntu-stable-xenial*
sudo rm /etc/apt/sources.list.distUpgrade
and reload the sources:
sudo apt-get update
After this, if you check the list of repos in the Softwares & Updates, you should have the four main Ubuntu repos (main, universe, restricted, universe) enabled in the first tab, the Partner repo enabled in the second tab and that's pretty much about it..
If you check Synaptic → local/obsolte, you should have only the openprinting package, the two skype packages and the teamviewer one. Is that correct?
