Cannot identify IP for eth0 or eth1

I am new to Asterisk. My computer had Windows XP previously. I copied Asterisknow image to CD and booted my computer from CD.

I chose Express Installation.
And chose remove all partitions.

My systems boots Asterisk, but it cannot start GUI Asterisk.

This is the error I keep getting (I tried to slove it by creating a new CD and installing it again – no use)

Cannot identify IP for eth0 or eth1, to start GUI.
Press Alt+F2 to boot to terminal mode.

It is asking me to configure an IP address and give me the following root.

/etc/sysconfig/network-scripts/ifcfg_ethx
you need to do sudo su to obtain super user access.

Please help me. Mine is a standalone system.