Disabling IPv6 on all interface in Windows Server 2008 R2

In the Network Connections folder, obtain properties on all of your connections and adapters and clear the check box next to the Internet Protocol Version 6 (TCP/IPv6) component in the list under This connection uses the following items.

This method disables IPv6 on your LAN interfaces and connections, but does not disable IPv6 on tunnel interfaces or the IPv6 loopback interface.

Add the following registry value (DWORD type) set to 0xFFFFFFFF:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents

This method disables IPv6 on all your LAN interfaces, connections, and tunnel interfaces but does not disable the IPv6 loopback interface. You must restart the computer for this registry value to take effect.