sorry to hear that cdkit3 , mines not crashed once in over 16 hours of play ...
im running Vista64 OS , nothing too special pc wise , runs it fine oh high settings , i would assume since its you that you have done all the usuals ?
checked your settings in game
and any error logs after crash ?
good luck is all i can offer mate , its a good game , took me 2 hours before i turned off the slow sequence kills though lol so anoying