Windows 2000 Internet connection suddenly doesn't work.

I don't know whether anyone can shed any light on this, a friend of mine has an older Toshiba Tecra laptop running Windows 2000 which she gave to me to look at as it wouldn't connect to the Internet. It was connected via a cable to a router which was itself connected to a broadband modem. Other computers on the network were able to access the web quite happily, however this one laptop just gave a "Page Not Found" message every time you opened Internet Explorer.

I checked all the usual settings (obtain an IP address automatically etc) did an ipconfig /release and /renew, uninstalled then reinstalled TCP/IP. Nothing worked! So in the end I took the laptop away and wiped it, reinstalled Windows 2000 and all the drivers from scratch, patched Windows to SP4 and installed all available updates. It then worked perfectly, connected to the web no trouble.

Two weeks later the exact same problem started occuring again, for no obvious reason the laptop will no longer connect to the Internet. Nobody changed any settings, my friend wouldn't even know how to! I have no idea why this would happen, all the other computers are fine!

You can see across the network okay, map network drives etc, just no web access.

Here is a copy of ipconfig /all if it is of any use to anyone...

Windows 2000 IP configuration

Host Name: laptop
Primary DNS Suffix:
Node type: Broadcast
IP Routing Enabled: No
WINS Proxy Enabled: No

Ethernet adapter Local Area Connection 2

Connection-specific DNS Suffix:
Description: Intel(R) PRO/100 VE Network Connection
Physical address: 00-00-39-82-95-56
DHCP Enabled: Yes
Autoconfiguration Enabled: Yes
IP Address: 192.168.1.3
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.1.1
DHCP Server: 192.168.1.1
DNS Servers: 192.168.1.1
Lease obtained: 15 January 2007 10.39.01
Lease Expires: 16 January 2007 10.39.01

Can anyone make any sense of this odd problem. I've never had it happen before and it's got me stumped.

Many thanks

Graham