Look at your modem and see if all the lights are on, this means you're connected. Make sure all the cables are connected properly. Grab your modem and look in the back, there's a little button. That is the reset button. Choose a pen or something like that, and use it to press this button. All the lights but one will be off. Pick the Ethernet cable on the back of your XBox 360, now wait until it connects again. The lights will turn on one by one. When all the lights are on, turn your XBox 360 on with a game inside. All the lights in the modem have to be on, only the middle one will be blinking. Now, in the game you have to sign in to XBox Live. It's now connected.