Welcome to the forum.
Do you get any error messages?
Do you see any warning, or error messages in Windows' Event Viewr at the time of the crash?
How much free, defragmented space is on that HDD?
I'm with John.
Have you ensured that any photos you add to your project have been resized to no larger than 1000x750 pixels (2000x1500 for high-def)?
What model of camcorder is your video coming from and what resolution is it? How did you get it from the camcorder to your computer?