The MSWin distribution of NEURON uses cygwin for its terminal
("interpreter window") and some other purposes. cygwin is very
much a live project, and each release of it comes with its own
bugs, which may affect NEURON. Some examples of this are
described here
https://www.neuron.yale.edu/phpBB2/viewtopic.php?t=121
along with Michael Hines's recommendations should you encounter
any such oddities.