Windows 7 internet problem?

I'd say its just a temporary thing, probably your isp doing some maintenance etc. I'm with talktalk, and its great most of the time, but now and again i either can't get on the internet at all or it goes on and off just like yours, sometimes its been like that for a day. If it was ok before and you haven't changed anything, then its best to just turn all off and try again later, i'm sure it will be fine, if not contact your isp. I know its obvious but check all leads etc are plugged in properly.