If you know or suspect you have lots of duplicate images on your hard drive(s), then you can easily identify and then remove them with a cleanup utility like Duplicate Cleaner Pro, which I have and like very much. However, if all of your images are part of a Lightroom catalog, then you shouldn't delete your duplicates without following a few preliminary steps. I recently asked Tim Grey about how one might best do this, and he told me he will be answering that question sometime this week in his Ask Tim Grey online newsletter.
Gerry
