So for the past 2 weeks I've been using my macbook and running the internet and it's all fine and good. I normally use ethernet for my internet but we've been trying to get wireless set up in my apartment. the other day my roommate was working on the wireless setup and the router while i was perusing the internet on my macbook with the ethernet plugged in. then all of a sudden, my internet disconnected and would not connect again since. it's not the ethernet cord, as my roommates (who have PCs) can still connect with the ethernet just fine, as I am using one of their computers right now. I'm not the most computer savvy and this is my first apple so I'm unaware of what my next step is. I've followed the apple instructions and network diagnostics to no avail. I can't reset my modem because of the way the ethernet is set up in my apartment building - there is no reset on the modem. what can I do?