Is it normal for a Windows machine to crash once in a while?

Almost all OSes can lock up from time to time. Normally it's down to a fault in one of the hardware drivers. Windows isn't unique in this regard. At various times I have had FreeBSD, Linux, OS/2 and OS X all lock up. (I even managed to lock up OS400 running on an AS/400, but that's another story.)

IMHO Windows has never been 100% stable. I have seen some Windows server systems running up to 400 days straight but that is very rare. It however is still not normal to have it lock up like that. Are you over clocking the computer at all? Have you run any stability tests on it to make sure you don't have something going bad or a heat issue or incompatibility problem? What's the temps the computer is running at and the room temps?

No software is 100% stable, if it be an O/S, application or game. To many lines of code and human error will always sneak in.

Naah, in that case all the computers that I've owned have been faulty. My latest rig is prime/ memtest/ endless hours of gaming stable yet sometimes something as simple as using a camcorder as a webcam can make it BSOD. Or what I did yesterday, during StarCraft 2 I switched from headphones to speakers mid cinematic and then decided to connect headphones back, but this time via the port on the speakers instead the computers own port. Game locked up like crazy.   But yea, I'm just saying, I never had a 100% stable Windows experience that's all. I wonder how other OS's are like.

all programs crash, you can't really prevent it; its just a fact of life

sidenote: Starcraft 2 doesn't like it when you attach headphones in-game (it locks up)

haha i always follow this:

http://en.wikipedia.org/wiki/Murphy's_law

It still holds true regardless of the situation