How can I modify windbg is using ring0 on single pc?

Thats right. However, I am just wondering, why livekd can offer debugging with one PC and Microsoft can't. Since livekd internally uses Microsoft kd or windbg, I am sure there has to be some (hidden??) interface for live debugging or probing. Anyone knows how livekd works?

Visu

read some microsoft.public.kernel or microsoft.public.windbg

livekd instalss a driver and fools the os to think it as a crashdump file
and fakes some context structures and redirects the ioctl to read the kernel memory

and the ms guys picked it upon that idea and implemented it in xp
as Local Kernel Debugging so it is a reversers contribution in some twisted
context

but in xp they dont fake context structures and such because they had the complete source code for thier os as well as russinovichs app