Limited/No connectivity problems - wireless adapter?

Hi everyone.
I have had my wireless router for over a year now and never had a problem with it. It's a belkin wireless G plus mimo F5D9230-4.

Last week my internet was disconnected by my service provider in error. The wireless worked up til then. They disconnected my internet and my wireless would connect but obviously no internet connection. So I called them up and they got it all connected up again.

As soon as my internet came back, everytime I now connect to my wireless internet I get a "Limited / No connectivity" message appear. I can't get into the router settings to check as I have no connectivity. So I hardwired it through cable instead of wirelessly. I get exactly the same problem when it comes to assigning an IP address - even when no internet is plugged into the router. So I used the reset button to reset to factory settings. This has been done as the connection is now back to its default name, but I still can't connect to it.

So trying to rule out my router, I tried to connect to my friend's connection - whose connection has worked previously. Her parents are connecting to their router without problem. But when I try to connect I get the whole "limited / no connectivity" message again.

Is this a problem with my laptop's wireless adapter (which is built in to the laptop)? I have tried plugging in my old USB wireless adapter I used with my old PC but it does not work, everytime I plug it in it says "This USB device has malfunctioned" so I'm getting frustrated now. Any help would be greatly appreciated.

At the moment I am in the lounge with my broadband plugged into my laptop directly.

Cheers guys
Carl