Check your internet connection. There are a couple of different things to check.
1. See if your internet works.
If it does then check your firewall to make sure it is not blocking the program in any way.
2. Go to Start and click on Run. Then type cmd and hit enter. Then type ipconfig and hit enter.
If it displays an IP Address, a Subnet Mask and a Default Gateway then you need to try something else.
3. Go to Network Connections and right-click on the connection you are using and select Repair.
Try to see the list again when the reapir finishes.
4. If none of the above work make sure that your cables are all fully connected.
Also are you able to connect to a server by typing connect <ip address> in the console?
