Cannot go on line with Explorer

I have an HP laptop and cannot connect wirelessly at home. Elsewhere i can. My cable modem is followed by a linksys Wrt54gs, and my computer says i am connected with an excellent signal. I have repaired the connection, upgraded the firmware in the router, checked settings as best I know how, buy each time i try to connect to the internet, I get the message "Internet Explorer cannot display this webpage" no matter what webpage i try to open. Does anyone know how to remedy this?

Another thing to try, click run in the start menu, and type in cmd and press enter on your keyboard. When the window opens, it will be black background and white type, type "ping yahoo.com", or any abitrary site. It should tell you if there is any packet loss or not. If there's not, then you've got a problem with your settings. Also, check and make sure that IE is not operating in offline mode. Another test, you can try installing firefox and see if that allows you to surf, if so, it must be an issue with IE.