Quote: "Have you checked to make sure that the LAN and wireless network connection (if you're using a laptop) have IP on auto detect?"
No. I have no idea how to do that - and that's a typical Windows "nerd" question where I have no idea what the consequences are of choosing/not choosing that option (I'm being rude about Windows before you ask

).
Quote: "A few things, might be obvious but you didnt state you had done them."
I haven't knowingly done anything.
Quote: "First, Check the router settings to see if any obvious settings are wrong."
I have no idea how to do that - or what the settings might mean.
Quote: "second,
Try this in the cmd prompt:
ipconfig /release
ipconfig /renew"
And what are the consequences of doing that?
Quote: "If thats not it, its a local windows setting, which i cant point you anywhere because the error message is very vague."
That's roughly where I started.

How/who/what/when determines these IP addresses anyway?
Interestingly, my wife and I have been playing games on our respective laptops for the last hour or so and suddenly I could hear faint music. I asked my wife if she could hear it and she couldn't. Then I realised it was coming from my laptop and it had nothing to do with the game - or anything else that I knowingly had open. I then turned up the volume and could clearly hear choral music. It was rather pleasant - but where on earth was it coming from? Could this be related to the other problem? Have we in some obscure way tapped into our neighbour's network? Food for thought - I'll check.
Afterthought: Regarding the auto-detect issue, I think the answer must be yes because whenever I go somewhere with a wireless network the laptop detects it straightaway. But what has that to do with either issue?