To switch between installed versions of PC-DMIS NC, you should first register the NC dll from the required PC-DMIS folder: regsvr32 ctrlrdefaults.dll
You then need to run PC-DMIS before you try to run the NC Server application. You can then use NC Server as usual.
For information on the NC Server operation, please consult the NC Server PDF manual provided with your NC Server application. You can download NC Server from the Universal Updater application.