You should have a backup copy of the User Sites folder at D:/Program Files/NetObjects/NetObjects Fusion 8/User Sites. (Where D is your programs partition; yours is probably C.) This crucial folder is part of my daily backup routine!
Just copy this folder into the matching location on the new PC, or copy its contents (or a single site folder) into the new User Sites folder on the new PC.
Then open NOF and go to File > Open Site and it will open the User Sites folder. Open the relevant site folder and double-click on the NOD file. Then it will be listed at the bottom of the Control Panel window.
No importing necessary.