Yes we need to know whether it is wireless or a normal cabled NIC.
If it is cabled then it will prb be called 'eth0' or 'eth1' - you can click on the picture of the computers at the top right of your screen in gnome (next to the time) click properties,
the next window that comes up shows what is happening with the nic in 'Connection>Name'.
You can type straight over the top of what is in there.... It probably says 'lo'. replace this with 'eth0' if nothing happens, try 'eth1' - then click 'configure' and apply all your settings (such as DHCP etc)...
Good luck!