Hi Tony:
Thanks for all the thought you're giving to this. I'm not very good at this and I proceed cautiously. However today I'm even more puzzled, though I guess I have reason to be happy. Most of the folders have their keywords today. I don't want to waste a lot of your time but let me mention a couple of things and perhaps end with a couple of questions.
First, let me make it clear: the images are all on external hard drives, both "masters" and backups, and all the caption, keyword, and copyright data is there. So I'm not going to lose anything. My masters are PSDs, but I also save in another folder the DNGs with LTR adjustments. Very few if any are on the desktop hard drives. But the LTR catalog backup was on the old desktop hard drive (C), and that's what I copied over to the new desk top (C), first by putting it on an external and then by uploading the external to the new desk top. It was my backup of April 19 that I uploaded to my new desktop.
Today when I opened the LTR catalog backups folder on the new drive it showed me two folders, one labeled LTR-2, the other LTR-4. When I clicked on the LTR-2 icon I got a window saying "LTR-4 has previously upgraded the selected catalog. Would you like to use the upgraded catalog instead?"
When I clicked the "Info" tab just below the LTR-2 icon it showed me that I have 102,377 photos in the catalog, and it offered me a button saying, I believe, "Please upgrade". Why would it offer me this option if LTR-4 has already upgraded the catalog?
Does upgrading the catalog have anything to do with updating the process version? I've read that this should only be done on an image-by-image basis, since some changes might be undesirable.
Now about that point that "most" of the folders have keywords today. Before I discovered that, I was thinking that maybe the quickest way to solve my problem was just to re-import the images from the external hard drives. Since the raw DNG files contain the LTR adjustments, would I lose anything by just re-importing them into the LTR library? Would they remain in their old process version, without being automatically re-processed in the 2012 version?
Thanks for sharing your knowledge on this. While it looks like the problem of the missing keywords has gone away--for reasons I don't understand--I appreciate the time you took to try to guide me out of the wilderness.
Best wishes,
Chuck