Respecting what follows, your corrections of my misunderstandings are solicited.
OK. The digest goes like this: 1. It is the case that all installs to my single user computer are for use by all users. 2. MiKTeX has a requirement that the user maintain any *custom* class, style, include, other tex files, and layout files. One may choose to use any of the directories listed in MiKTeX Settings, though it would generally be better practice to add a new path to the available roots, and store files in that root, thus obtaining an expected retention of setting in the face of MiKTeX upgrade. Of course, if the settings are lost, then the path will need to be added to any upgrade. The *user config* directory is indeed not yet made, as in mkdir. I also note that the *user config* *user data* and *common* roots may not be altered, at least via MiKTeX Settings. 3. To be sure, when I mentioned following the given advice, I did follow all parts. Particularly, I refer to the notions of reconfiguration for both LyX and MiKTeX. Thus, when I added paths for the missing texmf subtree, I not only added a root and subtree to MiKTeX, the FNDB was refreshed and Update Formats (thought this latter step may have no direct impact upon my current need) need), and also reconfigure and restart LyX. Both of these tasks have been performed multiple times, and these times being subsequent to alteration of roots and addition of files thereto. 4. I did alter the layout file to read \DeclareLaTeXClass[llncs]{article (Springer LNCS)} Upon thereafter reconfiguring LyX, the class was recognised. So, now I am moving along. I had previously altered this statement, to include [springer] and not [llncs], owing to some suggestion hinted by other layout files. The correction to the bracketed label brought access to the document class llncs. Thanks to all for all the help you have given. Perhaps some of this information will find its way into the LyX documentation. wrb