OS and HW: Debian Jessie x64 cinnamon on Lenovo G50-45I have just installed a new Debian Jessie (Debian 8.7.1 x86_64 Cinnamon) on a friend's laptop, and I needed to upgrade the kernel and some stuff, I was directed to these steps by a person in the #debian IRC chat with these 3 packages in order to get the WiFi working:linux-image-4.8.0-0.bpo.2-amd64_4.8.15-2~bpo8+2_amd64.deblinux-base_4.3~bpo8+1_all.debfirmwqare-atheros_20161130-2~bpo8+1_all.debThe problem I am having now is that I am unable to install anything.Every program I try to install, even simple things like DosBox, give me errors about dependencies that are unsatisfiable.What is the reason for this and how to remedy it?Log of terminal output:$ sudo apt-get install wineReading package lists... DoneBuilding dependency tree       Reading state information... DoneE: Unable to locate package wine$ sudo add-apt-repository ppa:ubuntu-wine/ppasudo: add-apt-repository: command not found$ sudo apt-get updateIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie InReleaseIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie Release.gpgIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie ReleaseIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/contrib amd64 Packages/DiffIndexIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/main amd64 Packages/DiffIndexIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/non-free amd64 Packages/DiffIndexIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/contrib Translation-en_USIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/contrib Translation-enIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/main Translation-en_USIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/main Translation-enIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/non-free Translation-en_USIgn cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20170117-02:05] jessie/non-free Translation-enReading package lists... Done$ sudo apt-get install software-properties-commonReading package lists... DoneBuilding dependency tree       Reading state information... DoneE: Unable to locate package software-properties-common$ sudo apt-get install dosboxReading package lists... DoneBuilding dependency tree       Reading state information... DoneE: Unable to locate package dosbox$ sudo apt-get install python-software-propertiesReading package lists... DoneBuilding dependency tree       Reading state information... DonePackage python-software-properties is not available, but is referred to by another package.This may mean that the package is missing, has been obsoleted, oris only available from another source
Default sources.list on Debian Jessie (Unsatisfiable dependencies)
debian;software installation;dependencies
The reason for this is probably bad contents of your software sources. To remedy it:Edit your sources, with your favorite editor, use nano if unsure:sudo nano /etc/apt/sources.listComment out (with #) all of the CD lines.Make sure there is something apart from the CDs;if there is nothing else, you may copy-paste the following complete list:deb http://httpredir.debian.org/debian jessie main contrib non-freedeb-src http://httpredir.debian.org/debian jessie main contrib non-freedeb http://httpredir.debian.org/debian jessie-updates main contrib non-freedeb-src http://httpredir.debian.org/debian jessie-updates main contrib non-freedeb http://security.debian.org/ jessie/updates main contrib non-freedeb-src http://security.debian.org/ jessie/updates main contrib non-freeupdate cache:sudo apt-get updateinstall whatever you need ;)It may be wise to consider some things, namely in this answer, these two:If you don't need software sources, you may omit deb-src lines. That means, if you currently don't need to compile any software by yourself, you don't need these lines, but since they don't hurt...If you intend to use only pure GNU free software, you may omit non-free from all lines, if unsure, or new to Linux, you will probably want to have some non-free software, though...