Unfortunately the troubleshooter is a great idea, but it doesn't really help. It's basically a simpler, more candy coated way of telling you the system can't automatically figure out what's wrong and fix it
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The problem could be a number of different things. First, check where the network cable plugs into the computer and make there is a link light. If the link light is active, go to the command prompt and type in "ipconfig /all" and see what IP you are getting from the router (you can paste the output here if you have trouble finding the IP).
It would also help to know what operating system both you and your brother are running on your respective computers. The manufacturer and model number of the router would help as well.