You MUST select the 'ASSOCIATE' option in the control panel settings to apply any setting changes you may have made.
Go to the WIRELESS menu on the printer and change any settings required.
From the WIRELESS menu options, press the '+' or '-' button until ASSOCIATE appears.
Press the Set button and select 'YES&REPORT'. The NC-7100w settings you have made will not be used and the printer will print a configuration page to verify the settings.