Internet connected but not working

Ever since Saturday I have had a problem with my computer, it shows that it is connected to the internet yet anything that uses the internet does not work.

On Firefox when I try to go to a website it usually just stays on the Mozilla Start Page and the rest of the time it gives me an error message. On Internet Explorer I get an error message saying the webpage can not be displayed. When I have tried to run other things that use internet they all act like there is no connection.

I have ran a Session Restore and that did not help. Also I have tried a different cable that I know works. Also I am using my Playstation 3 on the same connection and it is what I am using to access the internet at the moment .

I am running Windows 7 on my computer