Customer defaults: Gateway -> view operations -> view operations (tab) -> mouse wheel scrolling direction; choose desired option.
I know this thread is somewhat old, but I am new to using NX. I am using version 8. Is it possible to change this setting in NX 8.0? I got as far as Customer Defaults: Gateway -> View Operations. But there were only two tabs, View Navigation and View Sectioning, and I did not see the mouse wheel scrolling direction setting on either of those.