Thanks for the reply Aurick! My second monitor is actually a Cintiq, 1600x1200.
I did try maximizing my workspace with the suggestions in previous threads (tab to remove UI elements, etc). This did not help.
It seems like it is trying to open it on my primary display because I see the initiation messages and then my display cursor turns into a cross, but my canvas becomes untoutcahble until I hit my escape key.
EDIT: Some “fixes” I have tried so far - I uninstalled & reinstalled zbrush as initial fix attemept, but that didn’t work, so I uninstalled again and erased any zbrush/pixologic files and registry entries I could find and then reinstalled again, still no good. I also tried loading ZBrush withut any plugin-ins by holding shift at launch.