Network problems

[Exploration]

Sounds to me like the drivers are shot. I'd suggest going to the Device Manager and finding your network card in there, finding the manufacturer and model of the card and then going directly to their website for the drivers. If that doesn't work then it could be a windows issue in which case you could try a system restore to before the time it started playing up and see if that makes any odds. Failing that then my only guess is the card is probably on it's way out but in my experience components such as Network cards once in a blue moon type of thing actually give out and its usually software related. At least for me anyway.