Cannot conect to SpeedTouch Router

[#1]

I have recently signed up to Plusnet, and received a ST-516 1-Port Router through the post. Having followed all the instructions to the point of connecting all the cables and checking all the lights (all green, with the internet light flashing now and then), I then proceeded to open IE, and received ‘page cannot be displayed’ error message. Following the instructions, I then typed in the router address (192. etc.) into the address bar, but still received the ‘page cannot be displayed’ error message.
I then proceeded to turn off Firewalls, antivirus and remove the old 3G internet connection dongle program. Double checked cables.
Still no luck: ‘page cannot be displayed’ error message.
Reset router. reset computer. Left 10 mins.
‘page cannot be displayed’ error message.
Phoned Plusnet support. They said its all looks ok their end, says the router is connected to my computer, which ties up with the green lights on the router my end. They said clear catch, turn off firewall and antivirus, then leave for 20 mins. If that didn’t work then they didn’t have a clue what to do.
Cleared catch, double checked everything else was turned off, tried it again…
‘page cannot be displayed’ error message.
Turned it all off from the mains, left for an hour or so, then tried again…
‘page cannot be displayed’ error message.
It was late by this time so I couldn’t be bothered to ring back to Plusnet help.
I’m wondering if either the router is damaged as it was just left loose in a cardboard box no bubble wrap, or its my computer.
Tonight when I get home from work I will try pinging the router address etc.
I can’t find anything on the web like this issue, everyone else who can’t connect to the internet can at least connect to their router.
Is it just the fact that I’m running vista?
I would be grateful for any ideas on what the issue could be, or any ideas for me to try tonight.
Thanks.
EDIT: Don’t know if it is relevant, but a few days after the phone line was connected, it completely cut off. When we tried ringing what had been our number, it went through to some random person! We notified Plus net and it was sorted out the other day. We can make outgoing and incoming phone calls. I don’t know if this could be related though?

[#2]

Has the PC been connected to the internet before?
I ask because I had a similar issue some three years ago. It transpired that the ethernet socket from the motherboard had malfunctioned.
A new ethernet card solved the problem.

[#3]

As far as I'm aware it has only ever been connected to the internet via USB. Through a dongle recently, and previously a wireless receiver.
If there is a fault with the Ethernet socket then would the router say that there is a connection to the computer though?

[#4]

Sorry my knowledge doesn't extend to be able to answer that.
The PC I had would connect with a wireless dongle but not with cable.
.

[#5]

I had a similar problem when I started with broadband. Same router but that wasn't relevant.
In my case because I wasn't using broadband (before) I had a number of needed (by broadband) PC services switched off.
Same result as you. Router connected looking good but PC couldn't "see" it.
If memory serves me I had the DHCP Client service turned off as this wasn't needed for dial-up.

[#6]

I've turned on the 'automatically detect…' turned on as recommended by Plusnet and set ‘automatically dial’ to off.
Sorry but I can’t remember off the top of my head what they are called, but they’re under internet options.
Would this be the same thing or is there any other setting I need to change?
I don’t mind getting a new Ethernet card but I’d rather not spend anything if it’s not going to defiantly fix it.

[#7]

At this level of problem, you probably want to make sure whether the basic IP network is configured on the PC, and what can be seen from the PC.
That probably means use of more basic tools than IE, and probably use of the command-line and raw IP addresses.
The usual commands will be:
  ipconfig
  ping
  tracert
  route
  nslookup
and there's a bit of a guide at http://commandwindows.com/tcpiputil.htm
When your PC is turned on, and the ethernet cable is plugged in, then the ipconfig command should show that the PC has an IP address (probably 192.168.1.something) and there is a gateway of 192.168.1.254
If that information is missing, then your PC isn't configured on your LAN, and you need to work out why. Perhaps the wired connection is broken, and nothing can be seen. Or perhaps it is connected, but the DHCP process fails (which is the process where the router allocates an IP address). The "ping" command will help identify if your machine can see the router (Use "ping 192.168.1.254" as a command).
If the information is present, then you should be able to use the ping command to check that the router can be seen: Use the address identified as the gateway in the output of the "ipconfig" program.
If that ping works, then your PC is able to contact your router. You then have 2 things to check:
a) Can IE view the router's admin page? Look at http://192.168.1.254/
b) Can the command-line see anything out on the internet? Try these commands:
    ping 212.159.9.2
    ping 212.58.244.67
The first one tries to contact the "www.plus.net" server, while the second looks for "www.bbc.co.uk".
If the ping works, then you are connected to the internet at the lowest levels, and the rest of your problems are related to services running at higher levels.
The next level up will be to check whether DNS names are resolving correctly. Try these commands:
  nslookup www.plus.net
  nslookup www.bbc.co.uk
  nslookup 212.58.244.67
If these are failing, then there is a problem in the configuration of your DNS servers, either at the PC or the router.
That's probably enough to help identify what area the problem really lies in...

[#8]

More fundamentally
Is there an icon a bit like a monitor in the bottom left hand corner of the screen and does it have a cross through it.
Also if you go into Control Panel then Device Manager then click on Network Adapters is one showing up

[#9]

Whoop Whoop!
Finely got it running!
First, thanks to everyone who helped.
@ Wombat, thanks for the reply, but I had already left work before you posted it, so I’ve only just looked at it now.
I pretty much worked through what you said anyway.
Ping came up blank as did ipconfig, so guessed it must be a fault my end.
Eventually I tried reinstalling my network drivers and adapters etc.
And now it works!
So thanks again, and hopefully I wont need to come on here again soon for help!

[#10]

you could look at Chit Chat, a devious forum