I've had 3-floor success with the Asus RT-N16, which runs EasyTomato openwrt software that provides a lot of control over who can access what, when, as well as showing signal strength for each connection if you want to try to tweak your location and antennas. The router is around $80. As mentioned, placement is the key for wifi, or use multiple routers. If you can put the router in the center of the 2nd floor and minimize obstructions you'll get better coverage. I've got sub-optimal placement but still get decent coverage on 3 floors. If you've got IP phone and/or you've had problems dropping the cable connection intermittently, the Surfboard SB6141 appears to be a good choice to try to resolve connection problems as compared with last generation such as the SB5120 on Comcast cable. Knocking on wood, but one day after plugging in the SB6141 I ordered last week, no phone dropouts and no cable modem resets. For Comcast, if the automated registration doesn't work, get your cell phone out and call 1-800-Comcast to get the new cable modem registered. You'll need the MAC ID , perhaps from both your old cable modem and the new one; it may take 20 minutes or so. Charlie