When you install Lightroom CC and start the program, it will automatically find your old catalog and prompt you to create an upgraded version. You should accept that and allow Lightroom to do it. The new catalog will be created in addition to your older one. Since the drive letter has changed, you will see folders with the "?" And other missing files/folder notifications. It would be ideal if all of your images are stored within one master folder. Then, although would be necessary would be for you to right-click on the topmost folder and choose to update the folder location.
I would recommend that you not try to reorganize the catalog before it is upgraded. I see the potential for you to lose the editing on a lot of your images if you do that. I think it would be better for you to try to reorganize from within Lightroom after you have done the upgrade. If you want to reorganize without using Lightroom, you will still have to go through the process of updating the folder location. But I think this would be easier after you have done the upgrade.
Remember that the new upgraded catalog will be created in addition to your original catalog. The original catalog will still be there and available so that if you make a mistake you can always delete the upgraded catalog and start over again.
Great, thanks so much. I'll try that. I was going to change my folder hierarchy structure before updating, but maybe I'll wait and do that from within LR. I'm on a totally new PC, so LR won't know where to find my old catalog. I'll have to "Open" from my backup folder on my separate drive, or should I copy the most recently backed up catalog into the default LR catalog at the new install location and then run LR?
I'm not really changing the folder structure that much. Just renaming the top most folder that has the photos, and then moving that folder up one level so it's at the top under Pictures. Should I still do that from within LR?
Considering that type of change, you could probably do it either way. If you're comfortable with updating folder locations I suppose it would be easy enough to do using your system browser. It's hard to say. I would probably try to do it from within Lightroom. But that's just my preference.
>copy the most recently backed up catalog into the default LR catalog at the new install location and then run LR?
That's what I would do. It should create the converted catalog in the new location.