Thanks for the response.
It seems to be when I actually go into the actual in-game screen. I *almost* see the game screen and then I get the "windows had detected an error" type message, in fact it's kinda greyed out as windows trys to solve the problem or whatever that automatic pop-up says. Then it closes to desktop.
I haven't actually played in a while but I logged in and out frequently today and it seemed to happen every time I changed characters.
I am running a fully updated version of windows 7.
At one point I actually did get to log on and take two steps before it happened.