How long did you have the PC powered on? Over several hours, then I would say that bytes received should be higher than bytes sent if you're just surfing the internet. However, Windows is, as my friend say, a chatty OS. For one, there's a browser service (not IE or firefox) which tries to discover whats on the network. You could disable that service and see what happens. I was able to achieve a 'quiet' network with Linux - no router lights blinking when I'm not sending anything.