Ubuntu 14.04.4 LTS Ethernet not working

i have installed Ubuntu 14.04.4 LTS on my desktop PC and immediatly Etheet goes off.

That's my network configuration and some outputs:

ifconfig

eth0      Link encap:Etheet  HWaddr 00:1c:25:55:7f:af  
      inet6 addr: fe80::21c:25ff:fe55:7faf/64 Scope:Link
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:27 errors:0 dropped:0 overruns:0 frame:0
      TX packets:50 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000 
      RX bytes:4663 (4.6 KB)  TX bytes:12227 (12.2 KB)

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:159 errors:0 dropped:0 overruns:0 frame:0 TX packets:159 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:11454 (11.4 KB) TX bytes:11454 (11.4 KB)

sudo lshw -c network

*-network               
   description: Etheet interface
   product: 191 Gigabit Etheet Adapter
   vendor: Silicon Integrated Systems [SiS]
   physical id: 4
   bus info: pci@0000:00:04.0
   logical name: eth0
   version: 02
   serial: 00:1c:25:55:7f:af
   size: 100Mbit/s
   capacity: 100Mbit/s
   width: 32 bits
   clock: 33MHz
   capabilities: pm bus_master cap_list etheet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
   configuration: autonegotiation=on broadcast=yes driver=sis190 driverversion=1.4 duplex=full latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
   resources: irq:19 memory:fdffc000-fdffc07f ioport:fe00(size=128)

sudo gedit /etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)

auto lo iface lo inet loopback

sudo gedit /etc/NetworkManager/NetworkManager.conf

[main]

plugins=ifupdown,keyfile,ofono dns=dnsmasq

[ifupdown] managed=true

sudo gedit /var/lib/NetworkManager/NetworkManager.state (i have only Etheet, it's a desktop PC)

[main] NetworkingEnabled=true WirelessEnabled=false WWANEnabled=true WimaxEnabled=true

Some advices to let it work?