I'm connected to cox high speed internet 4mbps internet service. I have a router, and two PCs are connected to it. One PC is getting the 4 Mbps downspeed, but one is only getting around 1Mbps. The upspeed on both are fine. The PC with the slower connection has an onboard NVIDIA nForce networking controller, Windows XP SP2. Any ideas of why this PC is not getting the full 4Mbps speed?