Router: DIR-655
Network Card: Dell Wireless 1390 mini card
None of the computers could connect to the internet through the router (1 wired, 2 wireless). So I reset the router to the factory defaults. I had saved the settings on the router before reseting it, so everything should be exactly the same as before reseting it. The other two computers work. One is only connecting at 54 kpbs. The 802.11 mode is set to "Mixed G, N". It was connecting at 300 mbps before.
I am not sure whether this is related. When the "enable auto channel scan " is disabled, the other wireless computer can not connect. Before, when it was enabled, the computer could connect. I would rather turn it off and choose what channel I want.