The house is 3 years old and approx. 1 year ago water started dripping in on the right side top between the upper casing and the top window frame during a wind driven rain. I pulled siding off at top of window and it was dry! No evidence of rain/moisture/tracks on house wrap. The sheetrock on the interior shows no evidence of water damage. The upper bedroom window directly above it on the second floor does not leak and no water damage. It appears that the water is running down the inside of the OSB and hitting the top of the window and running out into the room - but how and where is it getting in. This only happens during a wind driven rain. Where do I start and what do I do now - of course we live out of town so nobody is interested in coming out for this little "problem".