Please elaborate on 'everytime it searches for the network, the Nook restarts'.
1) Are you going to the WiFi page, choosing the network and tapping on it to connect on it, and then it restarts?
2) Does it restart when you enter network password and/or connect to it?
3) When WiFi page starts searching for networks?
also, if it crashes during the process of signing on to network, please let us know what step it crashes at i.e. connecting, varifying, getting IP address, or something else?
Also, what apps do you have running? It might very well be that some app that uses wireless is the one causing the restart.