My brother and I decided to try some LAN play in Yuri's Revenge. I have TFD, and I installed the same TFD on my brother's laptop with same CD keys (obviously). We tried playing through the same modem, and everything worked quite well, until he tried to join my game, after which he got a message saying that the same CD key is already in use by the other player in the game, which is very understandable.
My question, is it possible in any way to play Yuri's Revenge LAN with the same CD key? Or is the easiet way to make my brother buy himself a copy of TFD?