Network is disabled

Can you give the output of:

sudo lshw -C network; lsb_release -a; uname -a; sudo rfkill list; dmesg | grep -i firm

Thanks

 *-network DISABLED
       description: Ethernet interface
       product: VT6102 [Rhine-II]
       vendor: VIA Technologies, Inc.
       physical id: 12
       bus info: pci@0000:00:12.0
       logical name: eth0
       version: 7c
       serial: 00:14:0b:41:9e:af
       size: 10Mbit/s
       capacity: 100Mbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical tp mii 10bt 10bt-f
d 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=via-rhine driverve
rsion=1.5.0 duplex=half latency=24 link=no maxlatency=8 mingnt=3 multicast=yes p
ort=MII speed=10Mbit/s
       resources: irq:23 ioport:4800(size=256) memory:c9400400-c94004ff
  *-network DISABLED
       description: Wireless interface
       product: AR2413/AR2414 Wireless Network Adapter [AR5005G(S) 802.11bg]
       vendor: Atheros Communications Inc.
       physical id: 1
       bus info: pci@0000:05:01.0
       logical name: wlan0
       version: 01
       serial: 00:16:44:8f:f5:9a
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=ath5k driverversion=3.2.0-24-generic
firmware=N/A latency=168 link=no maxlatency=28 mingnt=10 multicast=yes wireless=
IEEE 802.11bg
       resources: irq:18 memory:c9000000-c900ffff
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04 LTS
Release: 12.04
Codename: precise
Linux paul-laptop 3.2.0-24-generic #39-Ubuntu SMP Mon May 21 16:51:22 UTC 2012 i
686 i686 i386 GNU/Linux
0: phy0: Wireless LAN
        Soft blocked: no
        Hard blocked: no

 *-network DISABLED
       description: Ethernet interface
       product: VT6102 [Rhine-II]
       vendor: VIA Technologies, Inc.
       physical id: 12
       bus info: pci@0000:00:12.0
       logical name: eth0
       version: 7c
       serial: 00:14:0b:41:9e:af
       size: 10Mbit/s
       capacity: 100Mbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical tp mii 10bt 10bt-f
d 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=via-rhine driverve
rsion=1.5.0 duplex=half latency=24 link=no maxlatency=8 mingnt=3 multicast=yes p
ort=MII speed=10Mbit/s
       resources: irq:23 ioport:4800(size=256) memory:c9400400-c94004ff
  *-network DISABLED
       description: Wireless interface
       product: AR2413/AR2414 Wireless Network Adapter [AR5005G(S) 802.11bg]
       vendor: Atheros Communications Inc.
       physical id: 1
       bus info: pci@0000:05:01.0
       logical name: wlan0
       version: 01
       serial: 00:16:44:8f:f5:9a
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=ath5k driverversion=3.2.0-24-generic
firmware=N/A latency=168 link=no maxlatency=28 mingnt=10 multicast=yes wireless=
IEEE 802.11bg
       resources: irq:18 memory:c9000000-c900ffff
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04 LTS
Release: 12.04
Codename: precise
Linux paul-laptop 3.2.0-24-generic #39-Ubuntu SMP Mon May 21 16:51:22 UTC 2012 i
686 i686 i386 GNU/Linux
0: phy0: Wireless LAN
        Soft blocked: no
        Hard blocked: no

If you run:

sudo rfkill unblock all

Does it come up?

When I run "sudo rfkill unblock all" nothing happens at all.

Try:

sudo service networking stop; sudo service networking start

HTH

Results:

stop: Unknown instance:
networking stop/waiting

The network is still showing as DISABLED.

I found that when I built a laptop with ubuntu-minimal 12.04 I had the same problem on boot (to a command line).

When I ran...
sudo dhclient eth0
...it manually triggered something which I thought would have been triggered just by plugging the cable in, which is the negotiation of a DHCP address.

Magically the status against the device with 'logical name' eth0 in...
sudo lshw -class network
...changed from DISABLED and everything was working for that interface.

This got rid of the "disabled" status, but I am still unable to connect with the computer. Also, this appears to be a temporary fix as when I shut down or reboot I still receive the "disabled" indicator.

To make it permanent you have to ask for the network interface to be configured fresh on boot by editing a file /etc/network/interfaces as described here (note their typo in describing the path to the file)...
http://superuser.com/questions/151936/how-to-automate-running-the-dhclient-in-ubuntu

As for why your computer can't communicate even after negotiating a DHCP lease, it's possible that the network itself isn't configured to allow the machine to communicate.

Did you try pinging google to check the network is OK. On my machine it looks like this...

cefn@cefn-dell-oneiric:~$ ping www.google.com
PING www.l.google.com (173.194.66.99) 56(84) bytes of data.
64 bytes from we-in-f99.1e100.net (173.194.66.99): icmp_req=1 ttl=46 time=102 ms
64 bytes from we-in-f99.1e100.net (173.194.66.99): icmp_req=2 ttl=46 time=22.0 ms
64 bytes from we-in-f99.1e100.net (173.194.66.99): icmp_req=3 ttl=46 time=44.5 ms

Great then run:

echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf > /dev/null

Then get fully updated. Hopefully updates will fix stuff