Orientating Photos with Adobe Photoshop Lightroom

Lightroom uses EXIF data to determine the orientation of pictures automatically however, I have several old cameras that don't input such data into the photo. This leads to an issue I am currently going through.

When I use LR to manage my photos, e.g. rotating the pictures, the rotation occurs in LR however when I view the picture in Macintosh Finder or Windows Explorer, the photo is still in its original orientation. Is there anyway so that whenever I make changes in LR that it also appears in Finder/Explorer?

Is there any workaround for this? This will just make transferring the photos to another location (computer) more seamless, so I don't have to rotate again...

Note: even with my Canon 450D, LR detects the correct orientation but Windows Explorer doesn't.