If the photo viewer that you're using ignores the orientation tag stored in the photo's Exif data, then your photos will not be displayed in the correct orientation.
Windows® 7, its default applications such as
Windows® Photo Viewer and
Windows Explorer ignore the Exif Orientation tag. Use another app that can read this tag so that your photos will appear in the correct orientation.
Windows® 8 and later versions, the default photo viewer and File Explorer can support reading the Exif Orientation tag and will display photos properly.