LR4 on PC and Laptop help

Question

Hi,
I have LR4.3 loaded on my PC (with serial # and cd).
I imported files to DNG, made adjustments ect. And saved to a catalog on the PC hdr drive.
I repeated the above process several times.
From time to time I also backed up the catalog when suggested by LR.
I backed up everything to an external drive.
I recently bought a laptop and installed LR on the laptop and upgraded to 4.3.
When I try to work from the "external" hard drive, I can't open the catalog(s).
Any thoughts on what I did wrong or am doing or not doing?
Thanks

Answer 1

Yes, it is clear.
To achieve this two things have to be done:
1) your photos have to be moved from the C-drive to the external drive. I take it this has happened already since your screen shot shows the images on the C-drive as "missing".
2) the catalog ( = Lr database) has to be moved from the PC to the external drive. Since both computers (PC and laptop) need to write into the same catalog in order that you can see the edits done on the PC also on the laptop (and vice versa), they both need to have access to the catalog (= database). So it has to be on the external drive.
(Just as an aside: there is also a way to accomplish this with two catalogs (= databases) and merging them later on - but I think that would confuse things at the moment. So I am not elaborating on that).
To move the catalog (= database) to the external drive: find the file with he extension <  .lrcat>. By default it is in the folder <My Pictures/Lightroom> . If you can't find it, do a search for a file with < lrcat>. While Lr is closed move this file with Win Explorer to your external drive. I suggest you create a new top-level folder called <Lightroom catalog and Previews> and put the catalog file in there. You can also move the previews folder in there. The previews folder is a folder with the extension <  .lrdat>, and you will see it right next to your catalog file. Moving the previews folder is not critical because Lr will create new previews "on the fly" if it doesn't find any.
Once your catalog file (= the lrcat-file) is on the external drive (and your photos are also there) double-click the catalog file and Lr will open.
Since the catalog (= database) was created while the images were still on the C-drive, the link that Lr had established between the catalog and the image files is broken, and you see the question marks on the frames of the images (in Grid View) and in front of the folder names. Your screen shot shows that. Now you have to re-link Lr with your image files (= photos).
I gave you the two links in my post # 13. Read and watch the tutorial, and you'll learn how to re-link your photos.
Just one warning: Do not re-import your photos. Re-importing creates havoc with your catalog, creates unnecessary duplicates, and you loose your edits. The import is strictly for images only that have never been imported in Lr.
So, you have your work cut out. Good luck! If you run into problems, ask.