Someone Somewhere said:
Try a different cable.
Also, what does Windows say the link speed is (not the transfer speed, the actual physical connection speed)?
Hey, Just so everyone knows the solution was the cables. We make all of the cables in out house aside from a few using a standard crimper. It seems like the quality of the crimper or head was bad and the cables that we made would not go above 100mbps. Turns out a couple of store bought ones and only ONE that we made works at 1 Gbps. So everyone, when you get/buy a cable plug your computer directly into the router and make sure its quality is up to par!