"nothing happens" is not descriptive. Is it a white page, Page Not Found? What site are you trying to reach?
Can you ping google.com successfully? You did not say one way or the other.
I have seen viruses change the proxy which tends to give you a Page Not Found Error. If thats your error then check Internet Options, Connections, and then Lan Settings...
yes i can ping google. when i say nothing happens., i mean internet explorer displays web page not found (home page). I have then entered one of my favorites and says the same thing