Check the flow speed/duplex speed in your network card properties in device manager, and should be on the advanced tab. Make sure that its on full auto negotiation. I've also seen in a number of cases, its usually the cable you are using - try a different cable, or perhaps even a crossover cable if your nic and router automatically detect media type - shouild if they are both fairly new. try resetting, or power cycling your router too, and hey who knows, you may have just bought yourself a bad router