First off you could try;
Cmd> ipconfig > all.
here it should be giving you your ip, default gateway ect. If you default gateway and ip there then you should be along the right lines.
If they're not go into your routers config, via web interface; possibly - 192,168.1.1 [Default gateway]
Then check all your setting - use DHCP, assign auto.
Have a look round - Have you installed all the drivers or your computer? This is a common problem.