I have Diablo 2 and LOD. When I want to play LAN (and online) I have to have two copies of the game I am playing, Diablo II or LOD. I can't play LAN without 2 CD's because it wont let me boot up the game without the CD in the drive. I have tried removing the CD when the game has already loaded, so that I could boot up the game on the other PC, but that didn't work. I ended up just burnging a copy of my CD to use on my other PC. That works..
-Mak