When the first left for dead came out on the PC there was a split screen option so two people in the same house could play on the same PC with 2 xbox controllers
Check it out -->
http://forums.steampowered.com/forum...d.php?t=745113
Unfortunatly i think they have removed the code in one of the updates, i was just hoping number 2 had the option in aswell but i guess they have cut it out.