I've had this problem before, last time our power went out the same thing happened. I took it to a computer shop and I didn't get it back for another month and all they had to say was they didn't know what was wrong with it and to take it home it should work fine. When plugged into the internet at the shop it worked fine. After I got it back I took it home, hooked it up and it didn't work. So I turned around and went back. They hooked it up and it worked and said they don't know what the problem is, maybe my network. The guy said try again and call if it doesn't work he'll stop by and see if he can fix it. So I took the computer back home, plugged it all back in, and it worked fine.
So now I seem to be having the same problem, the modem is fine. It's a 2Wire from at&t. There is nothing wrong with the cables, I've tried multiple ones. I have no idea what the problem could be, but I'm hoping someone else here will, so I don't have to wait another month for nothing.
My Networks is also empty. I don't recall it being empty the last time I had this problem.