i have had l4d2 since it came out. i played with a few of you lately and kept having my comp lock up so that i had to do a hard reboot. i have tried several solution found in steam forums, but nothing is working. no matter if i play offline or online, my comp freezes and i have to hit the reset button. my keyboard and mouse both go dead. i have never had this problem before, and l4d is the only game i am having this issue with.