If you moved or copied the photos to the new computer and Imported them, then this was a mistake; stacks cannot be moved or copied this way; and in fact it is never a good idea to import photos that have previously been imported.
The proper way to move your Lightroom installation from one computer to another is given here: http://www.lightroomqueen.com/how-move-lightroom-to-new-computer/
Your advice solved my problem with the stacking in five out of the seven major folders. But, when I opened up the last catalogue created on the old computer (with a different file structure) I got my stacking back for the images that were on the old and new D drive. However, there were two large folders on the old C drive that were moved to the new D drive and those image are missing but all the keywords, stacking, slide numbering, flagging, etc. is in place in the folders at the new location, but not the images themselves. How do I reconnect the images with all the catalogue information for these slides? Thanks for the quick response to my last question and I eagerly await your last bit of guidance on how to correct the rest of the problem. All the best.
Reconnect the images using these instructions: Adobe Lightroom - Find moved or missing files and folders If the folders have a question mark icon, see Figures 3, 4 and 5, if not then start at the top.