I connect to Xbox live via connecting it to my PC as I have a USB modem, it usually works fine until the other day my brother decided to mess about with the "networking" tabs for both the LAN and the USB modem. I have no idea how to sort this out. Can anybody help me? I'm not sure what boxes to tick etc. out of the following

Internet protocol version 6
Internet protocol version 4
File and Printer Sharing for Microsoft Networks
QoS Packet Scheduler
Client for Microsoft Network