Scaricamento delle informazioni del repository non riuscito

Salve a tutti, non riesco a portare a termine l'aggiornamento software. Mi appare il tipico messaggio "Scaricamento delle informazioni del repository non riuscito. Controllare la propria connessione ad internet". La connessione è perfettamente funzionante. Se metto su terminale sudo apt update mi dà questo output:

Ign:1 cdrom://Ubuntu 16.10 _Yakkety Yak_ - Release amd64 (20161012.2) yakkety InRelease Err:2 cdrom://Ubuntu 16.10 _Yakkety Yak_ - Release amd64 (20161012.2) yakkety Release Usare apt-cdrom per far riconoscere questo CD-ROM da APT. apt-get update non può essere usato per aggiungere nuovi CD-ROM Trovato:3 http://archive.canonical.com/ubuntu yakkety InRelease Ign:4 http://archive.ubuntu.com/ubuntu yakkety InRelease Ign:5 http://it.archive.ubuntu.com/ubuntu yakkety InRelease Ign:6 http://security.ubuntu.com/ubuntu yakkety-security InRelease Ign:7 http://ppa.launchpad.net/jonabeck/ppa/ubuntu jaunty InRelease Ign:8 http://it.archive.ubuntu.com/ubuntu yakkety-updates InRelease Ign:9 http://it.archive.ubuntu.com/ubuntu yakkety-backports InRelease Err:10 http://security.ubuntu.com/ubuntu yakkety-security Release 404 Not Found [IP: 91.189.88.152 80] Err:11 http://archive.ubuntu.com/ubuntu yakkety Release 404 Not Found [IP: 91.189.88.162 80] Err:12 http://it.archive.ubuntu.com/ubuntu yakkety Release 404 Not Found Err:13 http://it.archive.ubuntu.com/ubuntu yakkety-updates Release 404 Not Found Scaricamento di:14 http://repository.spotify.com stable InRelease [3.302 B] Err:15 http://it.archive.ubuntu.com/ubuntu yakkety-backports Release 404 Not Found Ign:16 http://ppa.launchpad.net/jonabeck/ppa/ubuntu karmic InRelease Err:14 http://repository.spotify.com stable InRelease Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY A87FF9DF48BF1C90 Ign:17 http://ppa.launchpad.net/gilir/ubuntu hardy InRelease Trovato:18 https://deb.opera.com/opera-stable stable InRelease Trovato:19 https://dl.winehq.org/wine-builds/ubuntu yakkety InRelease Trovato:20 http://ppa.launchpad.net/gezakovacs/ppa/ubuntu yakkety InRelease Trovato:22 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu yakkety InRelease Trovato:23 http://ppa.launchpad.net/noobslab/themes/ubuntu yakkety InRelease Trovato:24 http://ppa.launchpad.net/otto-kesselgulasch/gimp/ubuntu yakkety InRelease Err:21 https://dl.winehq.org/wine-builds/ubuntu trusty InRelease Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY 76F1A20FF987672F Trovato:25 http://ppa.launchpad.net/jonabeck/ppa/ubuntu jaunty Release Trovato:26 http://ppa.launchpad.net/jonabeck/ppa/ubuntu karmic Release Trovato:27 http://ppa.launchpad.net/gilir/ubuntu hardy Release Scaricamento di:28 http://ppa.launchpad.net/jonabeck/ppa/ubuntu jaunty Release.gpg [307 B] Scaricamento di:29 http://ppa.launchpad.net/jonabeck/ppa/ubuntu karmic Release.gpg [307 B] Ign:28 http://ppa.launchpad.net/jonabeck/ppa/ubuntu jaunty Release.gpg Ign:29 http://ppa.launchpad.net/jonabeck/ppa/ubuntu karmic Release.gpg Scaricamento di:30 http://ppa.launchpad.net/gilir/ubuntu hardy Release.gpg [307 B] Ign:30 http://ppa.launchpad.net/gilir/ubuntu hardy Release.gpg Lettura elenco dei pacchetti... Fatto E: The repository 'cdrom://Ubuntu 16.10 _Yakkety Yak_ - Release amd64 (20161012.2) yakkety Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://security.ubuntu.com/ubuntu yakkety-security Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://archive.ubuntu.com/ubuntu yakkety Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://it.archive.ubuntu.com/ubuntu yakkety Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://it.archive.ubuntu.com/ubuntu yakkety-updates Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://it.archive.ubuntu.com/ubuntu yakkety-backports Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repository.spotify.com stable InRelease: Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY A87FF9DF48BF1C90 W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://dl.winehq.org/wine-builds/ubuntu trusty InRelease: Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY 76F1A20FF987672F W: Errore GPG: http://ppa.launchpad.net/jonabeck/ppa/ubuntu jaunty Release: Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY F104610CF0876AC9 E: The repository 'http://ppa.launchpad.net/jonabeck/ppa/ubuntu jaunty Release' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. W: Errore GPG: http://ppa.launchpad.net/jonabeck/ppa/ubuntu karmic Release: Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY F104610CF0876AC9 E: The repository 'http://ppa.launchpad.net/jonabeck/ppa/ubuntu karmic Release' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. W: Errore GPG: http://ppa.launchpad.net/gilir/ubuntu hardy Release: Le seguenti firme non sono state verificate perché la chiave pubblica non è disponibile: NO_PUBKEY 665F9AEFE1098513 E: The repository 'http://ppa.launchpad.net/gilir/ubuntu hardy Release' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

Scusate l'ignoranza ma sono una principiante. Grazie in anticipo!