How do I identify the cause of leaky windows?

Now that it is storming, we noticed some leaks around some of our windows and under a skylight. We can’t find any evidence of leaks on the walls/ceiling though, so it seems like the water is coming through the windows (or window seams). How can we figure this out? Do we call a GC to fix? or a Roofer?

1 Locate the leak, which may take some detective work. One strategy is to have someone spray a section of the window while you watch for leaks inside the house. You may have to remove some drywall from around the frame to see the leaks, because the water may be traveling along the wood after it enters.
2 Pry off the trim from the leaking area with a pry bar, and inspect the gap between the window and frame. You may be able to fill it with caulk. If you see rotten wood, chip it out with a putty knife, and fill the void with epoxy wood filler.
3 Check the trim and replace it if it is rotten. Nail it back to the window, and caulk all the edges with waterproof caulk. Let the caulk dry before repainting.