Hello, AlexGin, you wrote: AG> It turns out, what it is possible to install Debian c live-CD and it will be almost same, AG> as well as with DVD-1 (except for insignificant applications for me)? AG> Or I understand something not truly? From the point of view of setting it is all almost one and too, it is not important to install from what, then it will be possible to deliver all. The command "apt-get update" needs to be launched after update of the list of repositories "/etc/apt/sources.list". And "apt-get upgrade" updates packets, downloads, dearchives, configures and so on, the development scenario is sewn up in a file *.deb. For example, there was at us distribution kit Debian 8.1, and current low version 8.9. Numbering of versions: the First of them - the high version (major), the second - low (minor), the third - small changes (maintenance, micro). We update the list "apt-get update" and we put new packets old concerning the version 8.9.x, or better to say simply the last. If in the list of repositories to write stable then it will be considered as analog of current stable release, that is now it is high version 9. Or it is possible to register it explicitly, that is stretch. If we did not want to reinstall OS from zero updated the list of repositories specifying in 9 version and launched a command "apt-get dist-upgrade" then at us update to the newest high version, and then also to the newest low went. Therefore before setting it is reasonable to download the newest distribution kit of desirable major release, but it is not mandatory. That in Debian that in others GNU/Linux it is possible to produce migration from the version to the version. Simply migration of low versions practically is not noticeable, and here seniors "apt-get dist-upgrade" nevertheless is small event. As to DVD it contains more packets, and it only the first disk, and there is a lot of them. But they practically become outdated at once, therefore if the local repository is necessary it is necessary to use apt-mirror. At it the adjustments as how to swing, and in "/etc/apt/sources.list" the local repository on a disk, instead of a repository from the Internet then registers. Very conveniently on a notebook if the Internet is not present or it slow, unpacking with SSD happens very quickly. As a result there is CD, is DVD, but it is better Live because such distribution kit allows to come in Debian on the computer on which it is not installed. Differently a flash card or other carrier on which such distribution kit is written down allows to service the computer means Debian, to change disk partitions, to recover grub and much another. Still I recommend to remember such command, as "apt-cache search". If at update of the list of repositories "apt-get update" the program starts to swear on absence of signatures then it is possible to make so "apt-cache search keyring". There there will be different packets, but for my configuration, that which in "/etc/apt/sources.list" suffices: apt-get install debian-keyring debian-archive-keyring deb-multimedia-keyring Typed manually, whether therefore I do not know works, but as already wrote above, it is possible to use search in packets. Basically it is logical to put right after setting Debian these packets. As to other adjustments of repositories like "deb cdrom: [Debian GNU/Linux 8 _Jessie_-..." That can be deleted them at once as are not necessary. And one more nuance, we put that an old packet, it is configured, and then there is new, and at us for a new packet an old configuration, that is to us not always suggest to change a configuration, but we can sometimes want it. On this case there is a command dpkg-reconfigure which allows packets that is as whether it be we put them from zero. Thus it is possible to migrate from the version to the version, for example, 6.x => 7.x => 8.x => 9.x and so on not from the installation distribution kit. And migration in high versions also is not so noticeable provided that the stable branch is used, in which programs practically do not change the versions throughout all life of the high version, that is the reconfiguration is not necessary. All this time developers correct the found out jambs, plus is created by safety updates. Not all understand that more than two years between releases, and as a matter of fact are even more, as support of the old version goes any time and after an output new that leads to fair obsolescence of a software, just and it is necessary to achieve stability of preferentially all programs entering into the current high version. People as though about reliability, but are not able to use, and start to install just created distribution kit of the high version. And still it is possible to put the newest versions of unstable packets, that is here it the decision of obsolescence of programs, only then it is not necessary to cry, if something took off or somehow on another .