More detail? At what point, at boot up or after filling in information? What have you tried?
How about if you boot from the sdcard again and format cache and clear Dalvik cache, fix permissions (under advanced menu) and try again?
This guide is pretty old. You could also try this one (same steps, newer version):
[Guide] Back to B&N Stock 1.4.1 or upgrade to 1.4.1