Hi ab'ers, I play Halo online and my son now has his own computer and we'd like to go on Halo together but... We have copied the cd which will play single person game offline no bother, but when online we are blocked by Invalid Key message. This is probably because both comps have the same game key code. Does anyone know if there's a way round this. It's not like were copying and selling anything, we've already paid for the game but it seems a shame and a bit of a rip-off if we've to fork out again for another original just for this! Thanks!