How to transfer images...

I have been trying for days to obtain a way to export images from my "C" drive (pictures) into Garmin Homeport. These images are in JPEG Format so they are compatible with Garmin. When I attempt to import them into Homeport (Master List) it says they cannot be imported because they do not have a "Geotag". Henceforth, how do I Geotag them and in what program?
Thank you, Bob