problem in flight??

Im using Windows Vista and when im in the flight (everything is running fine) a window pops up saying Flight Simulator is have a problem we need to shut it down. It just cancels my whole flight and I cant save or anything. I think it was a new 737-400 that I downloaded but I just deleted it last night.
Can anyone help me with this problem? :-/
Thanks ;)
Can anyone help me with this problem? :-/
Thanks ;)