Really need help with my xbox , just got it?

I'm having the same issue. I received the Wireless N Adaptor as a gift and have been struggling with it since last night! I tried entering the info manually as well. However, I have not been able to locate my XBox's 'MAC' address. My solution appears to be a simple one, sell the adaptor on Craigslist, trade in my XBox and games, and get a PS3.