Microsoft recommends leaving IPv6 enabled and by default it is. However there may be certain scenarios where disabling IPv6 is desired/required. Unfortunately, simply unchecking the box for IPv6 in the network adapter properties dialog, does not completley disable it.
To disable it completely, the registry must be edited.
In regedit, navigate to:
Create a DWORD named “DisabledComponents”, and set it to:
When done, reboot the server.