I pay comcast for 50mbs internet service but only get 6mbs.. The router i have is d3.0 and my pc is more than capable of handling the speed.. I dont have any viruses.. Is that all am supposed to be getting?
Temporary - enable firewall on your PC, or better yet - download some LiveCD and boot from it (this would be some Linux distro).
Connect directly to the modem (without router), and repeat your speed tests. If you still get 6mbps, complain to yout ISP.