Cant connect to xbox live

Hello, i used to play on xbox live connecting through my laptop.then i moved the xbox downstairs for a while and now i wanna play on my laptop again but i must have done something to my computer becasue now when i plug the ethernet cord coming from the xbox into my laptop it doesnt agknowlegde it and nothing seems to work anymore...i know that you have to change the network to shared or whatever but the properties tab doesnt show up anymore either.someone help me im tryin to play some call of duty in my room asap