Wireless Internet Mystery

Recently my wireless internet simply stopped working. I have tried all of the usual stuff, reseting the router, the modem, calling my ISP (comcast), but nothing seems to work. I am currently connected directly through my modem, but when I try to connect wirelessly the computer says it is connected but I cannot go online.

I checked start/run/cmd/ipconfig and found that I was not recieving a DNS suffix or a Default Gateway. I’ve had this problem before (on different networks) and reseting the router and modem always fixed the problem. Now, though, resetting everything doesn’t fix anything. What could be the problem?