What's going on with my laptop? (Crash related)

My laptop screen randomly went black today and a little blue box with a lot of DOS-looking techno gobbledy-gook popped up saying that Windows has experienced and unexpected error and I should restart my computer and it was commencing a physical memory dump. Then it restarted itself and all of my log-in information for various sites I frequent (including Fluther) was lost for some reason.

I’ve never had this problem with this computer before. What the hell is going on?