The Apple system photos have the orientation data on them (EXIF tags) in a way that Microsoft systems dont recognize. You can get a dedicated camera APP to correct the problem but then it will take longer time for photos to be stored.
Also, like Bill touched on you can take photos in an awkward way (Iphone volume buttons pointing up) and the photos then are stored in the correct orientation for Windows systems without the need to read that EXIF data.
