You are saying that you have 2 machines that go through the router, but in the next sentence you say that 1 box is not directly connected to it. Can you explain this situation a bit further ?
I will be glad to help. I'm thinking that you have 1 box connected to the router and the other machine is hooked up with your 1st box. In this case if you turn off your 1st computer you can't get axx to the net from the second one obviously.