Zero before you do anything else, try hooking up your Xbox directly to the modem. make sure and turn the modem and the Xbox off first, connect your cable from the modem to the Xbox, then power on the modem and once its done initializing, turn the Xbox on. if you can get it to work that way, the next thing you should do is power down everything, PC, router, modem, Xbox, and any other devices that will be connected to the router. connect everything the way it should be then power them up in this order. modem, router, PC, then any other devices. I would probably power up the PC and make sure you can get on the internet then try the other devices.