Hey guys a friend of mine owns the game on steam and had the same "No Sound" problem so after he lent me his laptop to look at the problem i have found what causes it and how to fix it, The problem is caused by Xaudio2 used in the game, Windows 7 SP1 handles it differently to other OS's so thats why the problem only happens on win7, to fix the problem the best method is to install KB2533623 reboot and it should fix the problem (the other method is to install a new version of windows). Anyway that fixed the problem for him, if anyone else could test it i would appreciate it, Thanks