There should be a more complete RE-INSTALL / a (complete) REPAIR in case

[Spliff]

"The installer only copies DLLs to the UR installation path or a subfolder." - Which I had completely cleared before my last re-install. So it seems that my previous tries all had been to just overwrite the then current installation with a new trial, and obviously are NOT recommended in case of problems. Will have to remember the "correct" way next time. ;-)