Got a problem, my old man has a Thompson 330 modem (from BT) and I went to install a Netgear DG834G v3 modem. Went through the installation process fine, but when it went to finish it said it could not see it (can't remember the exact message). The wireless part works fine (wireless Vista laptop works fine) so can't see why it won't work through the ethernet. Any ideas? If not I'll just get a wireless dongle and set the PC up for wireless.

What exactly are you trying to do? Is there still a lets say DSL connection to the internet and you're trying to install another modem, connected via lan cable to the router, to establish a connection to the internet? This won't work.

I'm trying to change the modem from his Thompson Speedtouch 330 to a Netgear DG834G v3. He bought my mother a new laptop with built in wireless and the Speedtouch 330 isn't wireless, so I tried changing it for the Netgear and it didn't work via the ethernet cable, but the wireless part did work on the laptop. So laptop can get a connection via wireless, PC doesn't via ethernet, doesn't even see the Netgear connected.

If you plug in the ethernet cable of the PC into the Netgear Router, there should light up another LED at the front side of the Router, otherwise the cable, the network card, or the ethernet port of the router is busted.

All the correct lights are on, power, internet, wireless and the ethernet light (well, number 1 which is where the cable is inserted into the Netgear), so there appears to be a connection to the PC, but the PC doesn't seem to see it.

Ok, so you have to check, whether your pc get's an ip address of that router automatically or not. Could be done by click on START / RUN and type in cmd. In the black window type ipconfig /all You should get listed the IP Address, Subnet, Gateway and DNS server. You can verify this with a results of a laptop that already works. The only different should be the IP Address.

You need to un-install the Speedtouch from Add/Remove programs and in Network settings any Internet Connections. After reboot providing the NIC is Enabled it will use the ethernet connection.