The installation appeared to go smoothly. But LyX wouldn't start, I typed lyx from the cygwin bash shell, and it returned "The application has failed to start because cygaspell-15.dll was not found."
So I download the libaspell15 package and that appears to make everything work.I think libaspell15 needs to be added to the readme. I'm just now experimenting with Lyx.
Regards, Stephen