Wireless Network disconnected?

I'm not sure if I am understanding this correctly. Is your brother connected directly to the wireless router and if so why? The router should be connected to the modem which brings the internet into the house and then each computer should be connected via wireless to the wi-fi router. The only way he could disconnect you would be if he has software on his laptop that came with the router and he is blocking you somehow. If you can, get the disk that came with the router and load the software on to your laptop. Then change the password so he can't block you.