Not sure without looking at the wiring diagrams. Switches normally work by closing the earth return so I guess that yes, there would be power. As soon as the car moves, something is disturbed and moves causing a short. Usually these faults are intermettent. Unusual to find it happens all the time.
Try starting the car again and moving the doors open and closed to see if the fuse blows again. Also, see if the fuse is a shared one. ie, protects another circuit such as some kind of lights. The problem may not rest with the windows, but with something else that shares the fuse.
