Unable to browse net but msn is working fine

Hello,
I've been having this problem for a long time, i have a laptop equip with windows vista premium sp2, on intel dual core and 4GB ram the problem was when i am browsing the net sometimes i keep having errors that im not connected i have tried other browsers ex: comet bird, morzilla, internet explorer, google chrome and all are reporting that im not connected to the internet i refresh everything and cookies and firewall, but its not working, the weird thing is my torrent and msn is running fine that im able to complete my torrent downloads and chat with people with no problem, so far the only solution of this problem was for me to restart the laptop, is there any way to end this problem permanently?