Wireless Network

My client has got wireless built to his laptop. He had a problem with it so he brought it down to my house for me to have a look at. I plugged in my network cable from my wired connection to enable me to get the things that I required to solve the problem. However, when he got home, he rang me and told me he cannot access the internet at all. Shouldn’t the laptop be able to differentiate between wireless and wired, or is it still looking for the wired network?