I would power off every device and then add them back one by one. Start with the router and then power up each computer. Play with each device for a few minutes and make sure it works before you add the next device. That will help you determine when things fail. Also, I would verify that your Wifi router is running DHCP and not doing something crazy like fixed IP addresses or Mac addresses.
thanks for the reply.....
Everything works until i add the NC. The NC will connect and work but kicks my two Android tablets off and PC off the network.
Not sure about the last thing you mentioned about DHCP. How do you do that?
It seems to be the NC that is causing the probs- how to resolve it?