Reconhecer adaptador ethernet no Ubuntu 14.10

Question

Eu tento conectar-me à internet no meu laptop HP Pavilion usando o Ubuntu 14.10, mas há um problema que o Ubuntu não reconhece a conexão com fio ou o adaptador Ethernet:

Quando digito ifconfig , só mostra:

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:181 errors:0 dropped:0 overruns:0 frame:0
          TX packets:181 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:13318 (13.3 KB)  TX bytes:13318 (13.3 KB) 

Ao digitar ifconfig -a :

eth0      Link encap:Ethernet  HWaddr 00:00:00:00:00:00  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:181 errors:0 dropped:0 overruns:0 frame:0
          TX packets:181 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:13318 (13.3 KB)  TX bytes:13318 (13.3 KB)

Enquanto eu sigo as instruções:

link

Primeiro, diz que o "Cabo desconectado" para conexão com fio - embora o cabo esteja conectado - também o botão "salvar" ainda está fechado, mesmo depois de editar manualmente as configurações do IPv4.

Eu tentei seguir a resposta em: O Ubuntu Server não reconhecerá o ethernet

E aqui está o que eu tinha:

ifconfig -a | grep eth dá:

eth0      Link encap:Ethernet  HWaddr 00:00:00:00:00:00  

sudo ifdown eth0 && ifup eth0 dá:

RTNETLINK answers: No such process
Internet Systems Consortium DHCP Client 4.2.4
Copyright 2004-2012 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Após nano /etc/network/interfaces :

auto eth1
iface eth1 inet static
address 192.168.1.3
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 8.8.8.8 192.168.1.1 

Então sudo ifdown eth1 && sudo ifup -v eth1 deu:

ifdown: interface eth0 not configured
Configuring interface eth0=eth0 (inet)
run-parts --exit-on-error --verbose /etc/network/if-pre-up.d
run-parts: executing /etc/network/if-pre-up.d/ethtool
run-parts: executing /etc/network/if-pre-up.d/wireless-tools
run-parts: executing /etc/network/if-pre-up.d/wpasupplicant
ip addr add 192.168.1.3/255.255.255.0 broadcast 192.168.1.255     dev eth0 label eth0
RTNETLINK answers: File exists
Failed to bring up eth0.

Alterando eth1 para eth0:

safi@safi:~$ sudo ifdown eth0 && sudo ifup -v eth0
ifdown: interface eth0 not configured
Configuring interface eth0=eth0 (inet)
run-parts --exit-on-error --verbose /etc/network/if-pre-up.d
run-parts: executing /etc/network/if-pre-up.d/ethtool
run-parts: executing /etc/network/if-pre-up.d/wireless-tools
run-parts: executing /etc/network/if-pre-up.d/wpasupplicant
ip addr add 192.168.1.3/255.255.255.0 broadcast 192.168.1.255     dev eth0 label eth0
RTNETLINK answers: File exists
Failed to bring up eth0.

Como devo proceder?