Originally Posted by
antonsvideo
the built in Windows defender is often a troublemaker, I don't know if it allows exclusions, if yes, then do it
if no, stop the defender service for testing and see if Nof works correct, however, defender may have already prevented a complete installation?
also, Nof 2013 needs the latest update in order to work with Win 8.1, what is your exact version number
I am using Win7 so I can't be sure, I have no issues with Nof 2013 and Nof 2015 on the same PC (other than the list of known outstanding bugs)