Calvie expressed precisely :
What happened to the group "microsoft.public.access"?
Microsoft is shutting down their server. (They really don't care
enough about their customers to keep this basically cost-free service
running any longer.) The group still exists, and appears to be
thriving, on usenet though. You just need to log on to a different
provider. If your ISP doesn't provide NNTP access, I'd highly
recommend signing up for a free account at
http://www.eternal-september.org for what seems to be very reliable
service!