Erros no ubuntu 14.10

[chuva]

Boa tarde,

sou iniciante neste sistema operativo, e não tenho experiência praticamente nenhuma em linux e ubuntu.
Acontece que adquiri um computador com o ubuntu 14.10 e estou a ter várias dificuldades, que me parecem dever ter algum problema de princípio comum.

1- Tem o libreoffice instalado mas não aparece o libreoffice database, coisa que eu necessito e queria descarregar.
2- Não consigo visualizar vídeos nem ter som, embora consiga visualizar vídeos no youtube. (aparece que devo instalar o flash player)
3- SEMPRE que tento instalar algum programa no software center, dá erro tipo "instalation requires unauthorized packages"
4- após algumas pesquisas, tentei fazer update ao sistema, mas dá erro:
The information about available software is out-of-date
To install software and updates from newly added or changed sources, you have to reload the information about available software.
You need a working Internet connection to continue.

Fica a fazer o "updating cache" e depois diz-me:
Failed to download repository information

Check your Internet connection.

Details:
W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/main/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/restricted/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/universe/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/multiverse/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/main/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/restricted/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/universe/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/multiverse/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/main/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/restricted/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/universe/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic/multiverse/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/main/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/restricted/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/universe/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/multiverse/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/main/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/restricted/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/universe/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/multiverse/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/main/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/restricted/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/universe/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-updates/multiverse/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/main/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/restricted/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/universe/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/multiverse/source/Sources  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/main/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/restricted/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/universe/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/multiverse/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/main/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/restricted/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/universe/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://pt.archive.ubuntu.com/ubuntu/dists/utopic-backports/multiverse/binary-i386/Packages  404  Not Found
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/main/source/Sources  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/restricted/source/Sources  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/universe/source/Sources  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/multiverse/source/Sources  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/main/binary-amd64/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/restricted/binary-amd64/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/universe/binary-amd64/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/multiverse/binary-amd64/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/main/binary-i386/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/restricted/binary-i386/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/universe/binary-i386/Packages  404  Not Found [IP: 91.1...]
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/multiverse/binary-i386/Packages  404  Not Found [IP: 91.1.....]
, E:Some index files failed to download. They have been ignored, or old ones used instead.


Alguém pode ajudar? 

[Tota]

Olá

O Ubuntu 14.10 saiu dos repositórios oficiais e migrou para os repositórios old releases.

Ou você ajusta seus índices para old releases ( old-releases.ubuntu.com)

Ou você atualiza para o Ubuntu 15.04
Em terminal

Código: [Selecionar]

sudo update-manager-d
Ou você descarrega o Ubuntu 15.04 e faz uma nova instalação "por cima" da sua 14.10

[clodoaldops]

Ubuntu-14. 10 já está sem suporte desde julho-2015
Eu faria bkp de meus arquivos e instalaria ubuntu-14.04.3-lts que terá suporte até abril-2019

[NathanRodriguez]

Outra vantagem das versões LTS como a 14.04 é uma maior estabilidade do sistema, priorizada nessas versões.