6over4 is included in the Microsoft Research IPv6 stack, Windows XP and the .NET Server family but is disabled by default. By the very nature of the 6over4 transitioning method, an IPv4 multicast enabled infrastructure must be available for 6over4 to be able to work.

To enable 6over4 type:

C:\>netsh interface ipv6 set global 6over4=enabled

at the command prompt. This will create a new 6over4 tunnelling pseudo-interface for each IPv4 address assigned to the host.