I'm going to make the assumption that someone from Microsoft did not go out to take that photo, nor did they take the time to create that photo.
I have a strong feeling they went to a commercial stock agency for it. I'm not pro when it comes to island types or even the probability of whether or not they can produce a certain type of vegetation, but I'd be willing to bet the location is real.
I do believe that for what's all going on, it does look fake. Their is a sailboat (w/ wind engulfed sails) with no apparent wind anywhere else in the image. Now, there is a possibility that the sailboat has a moter (actually, there is a very high possiblity it does), but usually when there is no wind, a sailboat will drop it's sails if running on just a motor.
I haven't been in enough places in the world to say for certain however that it is in the ocean. That could be a lake or a bay somewhere.
I do know, that creating that image in Photoshop would be extremely easy. I could probably do it in 5 minutes.
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