Multiple Networks Block Internet Connection

I'm running Windows 7 64 bit on a computer I built with an i7 920 CPU on an Asus P6T motherboard and 6GB of DDR3 ram. Every time I try to connect via Cat 5 wired DSL connection it adds an additional "Unidentified network (public network) and lists "Multiple networks under the middle icon on the Network and Sharing Center with a red X between that and the Internet. I have tried everything to get rid of the extra network but nothing has worked. It initially worked fine, but after getting a "critical update" it began to do this intermittently, now it does it all the time.