TCP/IPv6 protocol is not yet in use and having it enabled can cause connectivity problems.

DISABLING IPv6 in Vista
Unlike Windows XP, IPv6 in Windows Vista cannot be uninstalled. However, you can disable IPv6 in Windows Vista by doing one of the following:

* In the Network Connections folder, in the Properties of each of your connections, 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 0xFF:
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.



Warning: If you are not familiar with editing the registry of a PC, you might be better to avoid the second option above.