1) Check is make sure the network connections are listed in Network Connections. If not, you will need to install the drivers.
2) If they are listed, open up the Command Prompt, and run this command: ipconfig. If they are showing a valid IPv4 address - will start with either 10 or 192 - example is 192.168.0.101. Also, make sure it shows a default gateway - example will be 192.168.0.1
3) Run this command if they show the correct information: ping yahoo.com. If you get replies, then it's connected.
4) If step 3 fails, call your ISP at that point.