Setting up New Extreme

MacPro 2008, latest OS, latest Airport Util (6.3); when I replaced my old unit (Extreme Ver 5.0) with new (A1521), the new Airport Extreme would not connect to the Network, nor did iy see my Airport Express that I am using to extend the network. I have multiple networks--including a 5Hz and a Gust Network. I was trying to create a Network settings file which I could use to recreate the old networks on my new Extreme. When I open Network settings and select a particular Network and then access the scroll ladder (next to the +/- box at bottom of list)--the Export Configurations line is grayed out. Is there any better way to save your old saettings to use when you get a new Extreme?anyway to simplfy the new connections. Additionally, the new Extreme would not connect to the Internet yet modem ok and green lights on the back of the Extreme showing connections active; nor would it see the Airport Express extender I set up. Thanks in advance for asny suggestions