Boot into safe mode, see if you have the same problem. If you don't its software causing the problem, most likely antivirus or firewall products. Try uninstalling/disabling from startup your AV/FW products (disabling it from the system tray icon won't help most of the time). If it doesn't work in safe mode I believe there are some .dll files that need to be re-registered to fix
it. You could also try running these two commands in an elevated command prompt.
netsh int ip reset log.txt
netsh winsock reset
Also, you could try disabling IPv6 (including hidden tunneling adapters) by adding this registry key -
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters and create (if it doesn't exist) a new Dword called "DisabledComponents" and put either 1 to disable tunneling adapters or 255 to disable IPv6 completely.
Alternatively you could also go to Device Manager, click View -> Show Hidden Devices and disable everything you don't need (isatap adapters, 6TO4 adapter, teredo tunneling adapter, etc).