Your transcript will tell colleges what NC means in the context of your school. If it does stand for an F or a D, it will be counted as an F or a D (A rose by any other name....). If it means you dropped, I doubt they'll care as much.
I am not quite sure as to what my HS consider this as, I am guessing it is the "pass no credit," which means I passed the course but did not bother to get a letter grade for it....