I've just about had enough of this now. I've been searching for nearly two days for a solution.
Okay, so, here it is. I basically need a step by step instruction guide here as I haven't got a clue how to fix this.
Anyway, about two months ago I had some money problems and was forced to move in with my dad. I have a 20GB Xbox 360 and Xbox Live. I knew my dad had the internet so I could still use Live.
I have been doing so via an Ethernet wire going from my laptop (connected via wireless to the router) to the Xbox. A few days ago, I took my laptop to my cousins house and took my laptop with me. Connected it to his router via Ethernet as it was easier.
Come back home, want to play some Gears of War, plug in the Ethernet to the Xbox, and....
"Unidentified Network, No Internet Access", check for a solution and I get "Local Area Connection doesn't have a valid IP configuration"
Please help me before I rip out my beautiful long hair, haha.