Are you 100% you entered the info correctly.
You also have to ensure they both support the same wireless security(WEP/WPA/ECT. WEP sucks so use WPA/WPA2 if your can).
A test would be to change the wireless key in the router and try again, just in case you are not typing it right. I use wireless so infrequently that sometimes I forget my own key when I have to add a device