My problem is that I ruined my network driver or something like that .
sudo vi /etc/network/interfaces and edit the file like
auto eth0 iface eth0 inet static address 192.168.1.100 netmask 255.255.255.0 network 192.168.1.0 broadcast 192.168.1.255 gateway 192.168.1.1
I didn't change netmask and broadcast.
After that I issued the command
sudo /etc/init.d/networking restart.
Then Ubuntu crashed. It didn't show a thing only a terminal that's not responding. I restarted the system and there wasn't a sign that he could possibly connect to the Internet. Please help me. How I can make my Ubuntu 12.10 HP laptop and make the IP address a static IP address?