Mouser, thanks VERY much for your quick and helpful response. The problem was that when I first opened LBC, what opened was the new version, even though I had transferred my old files to the LBC directory in Program Files. But after I read your message, I went to the launch1.mcf file, right-clicked, and told it to open with LBC. Bingo! It opened and showed me all my nodes. But now I had two LBCs in my system tray, and I wasn't sure how to get rid of the one I didn't want. I'm still not completely sure how it happened, but when I closed both and then clicked on the LBC desktop icon, it opened the right version. I then rebooted to see whether that would be the version that loaded at startup, and it was. So I think that all is now well (except, of course, for the oversized set of nodes that I wrote about in a message on the forum not long ago).
Again, many thanks!!