It can thwart this when it expires so I've learned to remove that.
A friend has given me his Dell laptop to have a look at, but it's only the second time I've seen/used vista....
It seems to connect to the networks fine and picks up valid IP/DNS and router info, but it won't see any devices on the network in 'Networking and Sharing Center', and in IE 7 any page address entered (including ones on the network via IP address) result in an error page "The address in not valid" and the address is changed to 'http:///' note the three '/'.
I've reset the browser settings:-
checked the entry in the registry and everything I can find.
He has Norton's Internet security installed which didn't find anything, I've checked it with SUPERAntiSypware, and IObitSecurity360, even removed the hard disk, stuck it on my machine and then scanned the drive with McAfee A/V as well, and no luck so far.
At one stage it would download MS updates so I ran all the updates even installed IE8 and still no joy....