The .bat file!!! I seem to remember something about that....I think I tossed it thinking it was a DS file (it gets so confusing today and it's been a long strange trip!)
Thank you @parkdalegardener  I will look into that!

Y-Phil: my two old runtimes are on D:\ - - Same as they where when I was had P11 and P12 on the old computer.
Trying to set them up to be one for people and one for environments/props and one for animals (three total...trying to be more organized this time).

@FVerbaas; you lost me there - "create a dummy Poser.exe"?? I have never done that one before.
Normally I just create a folder called called "Runtime xxx" then put my files in the way Poser itself would set them up, then once in Poser I click Add Runtime  and point to it/them.
Is no longer a valid way, it worked up to P12 just fine??

****going back to find those .bat files! I think that might be the key!