Laptop not connecting to the internet - help!

[NotAnotherBrick]

One of my laptops has suddenly started not connecting to the internet. It says it's connected; there's a wireless signal that comes and goes. When I open firefox or IE though, it says it's working offline. My other laptop connects fine.

When I ask it to repair the connection, it gets stuck on 'renewing your IP address' and gets no further.

Can anyone help? It is very, very annoying having it not working as all my files are on that one!

And why does the wireless connection come and go on that one and not on this one?

Right, I've found it. It's the same IP except for the last number so ..1.1 whereas this (working) computer is ..1.2

So I've tried making hte broken one have the IP address is ..1.3 but it's not worked so far. Shall I just keep trying to change it?

Ah, hang on, it's also asking for DNS server info. Where can I find that? Can I use the same as the working computer?

But don't know how to find them on working computer.

Have you looked at the range of IPs available? If your pool is too small, you won't be able to assign it.

So your IP range needs to be

.**.1.2

through to at least

.**.1.6

to give you spare addresses.

It's a massive pool.

Right, good news is it says it's connected. Bad news is that I'm still waiting (20 secs now) for browser to actually prove it's going to connect.

Oh My Word!

The browser still won't actually connect! I have a signal; it is no longer saying that it isn't connecting; but the browser is still offline!

You have been so patient and kind and helpful! Are you all out of ideas?

Right, I have more info. One icon (little computer) says it's connected (which it used not to) but the signal strength thingy (four bars thing) says 'authenticating' still.

Is the DNS server an issue? I can't find what to put into that bit.

Trying bring up a DOS/Command window.

On windows XP it's in the start menu under Programs/Accessories.

You should also be able to get to it by clicking Start and then entering cmd in the run box.

Once the window opens up try typing:
ping 212.58.244.58

What that will do is see if we can see the BBC news web site by it's number rather than it's nice name.

It'll check internet connectivity without needing a DNS server.

Ooh, thanks! Just got back home, so will try that now. But what do I do if that works?

It's just saying 'Request timed out' despite an apparent 'excellent' signal :(

What next!?

You are not connected to the internet, it's not a DNS issue.

In the same DOS box enter the following command
ipconfig /all

And do try and hunt around for that network cable, it will remove one of the flakiest parts of the equation the wireless bit between you and the internet.

Do you know if your router is locked down to particular MAC addresses? I think that you said you'd found the admin page, go hunting through it and see if in the security/restrictions pages there's any mention of MAC addresses...

Thanks Badgers. My sisters boyfriend has diagnosed the issue over the phone, and my mum's going to take him the laptop so he can have a go at fixing it. He says it sounds like a network card issue.

Fingers crossed!