This is a pretty rare occurrence, but I occasionally find that I have multiple copies of the same folder of images in two locations. For example, I might need a copy of a folder of images to use in a demo, or I might have changed my mind as to which folder of images (the one on my internal or external drive) contains my “working” files, or maybe I’ve just plain gotten confused and have made duplicates for some unknown reason! Note: I just want to be clear, here I’m talking about an identical folder of images, that for whatever reason, appears in two different locations – not copies for redundant backup purposes.
Instead of deleting the unwanted folder from the Lightroom catalog – because that would remove the files from Collections, delete any virtual copies and, if I haven’t saved information to the files, discard metadata changes and develop settings, I simply Control -click (Mac) | Right Mouse -click (Win) on the Folder and choose Update Folder Location. Then, I navigate to the folder/images that I want Lightroom to work with and select it, enabling Lightroom to “keep track of” that set of images and forget about the others.