[total windows crash]

Started the game, alt tabbed to disable avast! firewall and allow full acces to the game, and started with a race no problem.  The game loaded and I went to have a cig.  When I returned after about 5 minutes, game was completely frozen on the laptop and music was stuck in an infinite 1 note loop.  this has happened multiple times in game, within about the first 10 minutes after map is generated.  The error always results in a complete computer freeze, and I have to hard reset my laptop.  Let me know if the error file shows anything.