DNS problem in a home network. IE explorer and Firefox stop working instantly

Hi

I have 2 machines on my home network. One XP and one Vista. The router is D-Link. I also use Network Magic.

The network used to work fine.

The Vista machine cannot connect anymore to internet, it sees the Router. I can even ping web sites. But IE and Firefox stop working immediately. "I E has stopped working".

Went to Messenger's options. Connection. To solve the connection problem. Everything seems fine except DNS and Main Ports.

Fix it does not work...

I rebooted the router, the broadband modem. I flushed the DNS cache. To no avail....

The router is working fine as the XP machine has no problem connecting to the internet. So either:

- the router messes up name resolution for the Vista machine ONLY, or,

- the Vista machine has a problem

BTW I reset all IE parameters. Did not work (which makes sense since Firefox has the same problem)

I am puzzled !!!!!