A. IP version 6 was first discussed in 'What is IPv6?'
Microsoft has released an Alpha release of IP version 6 (this is Alpha so not even Beta state so don't use on any live systems) which can be downloaded from http://research.microsoft.com/msripv6/. It installs on Windows NT and Windows 2000 installations but not Windows 95 or 98. The stack does not replace the IP version 4 stack but sits beside it allowing normal IP 4 connectivity to continue unaffected.
You can actually download the source and not just the images if you are interested.