So the question is...are you able to open your comp and remove Ram sticks? If so, I would pull out all the sticks but one, and then run some memory intensive apps for a bit. If it doesn't blue screen, open up your comp and pop in another stick. Repeat until you blue screen. Odds are, the last stick that you put in before you blue screened is the one that is bad.
Keep in mind though, you may have more than one bad stick.