I also get this problem 1 or 2 month ago this problem caused because i was installed a network which changed my IPv4 and IPv6 settings then i was bought i new card ( I thought my Lan card problem ) but still it not working then i Re window my pc then its works correctly. Maybe you install a new client or what you installed that changed your IPv4 and IPv6 Setting try to restore files by firewell if not work then search on google you find some help there if you cant search then Re window your PC.