This could be hard to understand.
I lost the association for .nwc files. So I re-associated them from the file types tab, but without any paramaters. Now when I open more than one from a folder, another instance of NWC opens and wont play.
So can someone please tell me what's in their "Open" action after Nwc32.exe
You need to re-run the setup program which installs NWC and sets up the file associations.
There is nothing after Nwc32.exe, but then down below "Use DDE" is checked. The form is filled out with "DDE Message:" containing "[Open(%1)]", "Application:" containing "NWC32", "DDE Application Not Running" left blank, and "Topic:" containing "System". Good luck!