Norton Internet Security Firewall blocks CableCard. You need to create a couple of new firewall traffic rules. Try this: Allow, Direction: In/Out, Computer: Any, Communications: Any, Protocol: All (Make sure the box is checked and move this rule up to the top of the list of rules) Also scroll down close to the bottom of rules and uncheck the box for this rule: Default Block UPnP Discovery Block, Direction: Inbound, Computer: Any, Communications: Specific, Protocol: TCP, Tracking: Create a log entry. Also go into trusted devices under settings and add the ip address and mac address for your tuner card(you can find these by right clicking on the network icon in the tray and then network and sharing center then on the left hand side of screen change adapter settings then double click on tuner card and then details button. MAC address can be found in media center during setup. Hope this helps.