Why cant i get on the internet?

just put a new hard drive in my laptop and re installed windows 7. I have a built in wireless card and all the software came installed from the factory. Usually I have no problem locating my wireless connection and many others but now it shows no connections. I have charter internet and a wireless router from linksys. What is the problem do I need some type of software installed from my internet provider or linksys ? Again I don't have any of the original programs from toshiba since I did a clean sweep to install windows. Please help me if you have any ideas. Thanks