Connected to Wifi but cannot browse internet - Infection?

I have a toshiba laptop and I have a wireless device that I use in order to get internet connection. I tried to log onto it lastnight and I noticed under the network and connections it shows that I can connect to my wireless device but there is not internet connection. when I try to connect to any internet site it reads this page cannot be displayed because of internet connection. I need to fix this problem quick. I tried to trouble shoot and it seems like there may be some sort of virus on it. I know that I can download virus protector or some sort of spy ware but it will not let me connect to the internet at all. Please help me out on this. I am not trying to go and spend an arm and a leg with geek squad!!