I have a wireless network at my house. My wife's computer connects just fine to it and the internet (I am using her computer wirelessly to ask this question).
My computer will wirelessly connect to the network, but I cannot access the internet via my wireless connection. (I tried to ping google and that fails too.)
If I connect to my wired network at my house the internet works just fine.
I can also connect to other wireless networks (and through them the internet) at other places (at the in-laws and on the commuting on the train).
I know I am able to connect to the network because I am able to access my router over my wireless network. I get an IP address. Every thing seems fine. But when I try to access the internet both Firefox and IE give me the unable to connect page.
Any Ideas on what I can check to fix this?