Vista - Internet stopped working

Hi there,
Last time I rebooted my computer internet suddenly stopped working. My network connection say it's still connected, active and transferring data. I can use vista update, I can ping google in a command line.

Whenever I try to use an application who use internet, it crash. Most of the time it's when I close the application that I receive the crash message. This is true for browsers like IE and Firefox. When it is running, it says it can't find any host.

I have Asus ExpressGate on my motherboard (a embedded linux) and internet work fine in it. It also work fine on another computer in my LAN.

The previous session before I shut down the computer I downloaded a file and NOD32 warned me about a virus called Trojan.Downloader.delf.OIS but stopped and deleted it before the file was entirely downloaded anyway. I scanned with multiple antispam/antivirus afterward with no results.

All application I use like MSN messenger, games, can't go on internet. I can't even access my router with either firefox or IE and it has never happened before.