Windows Vista? How about Micrix...?
"What will happen when Microsoft releases its new Linux distribution: Micrix (pronounced mick-rix)? It is everything you want.
It is completely cross-compatible with Windows, other
versions Linux and the Mac OS. Microsoft indemnifies you
against lawsuits from companies like SCO who claim Linux
infringes their copyright.
If you are running Microsoft software already then it is
supported as part of that licence, and even home users get
free telephone support."
Full article here:
http://news.bbc.co.uk/1/hi/technology/4727267.stm
.
Funnily enough - and as a side note - I'm posting this from Xandros Desktop 3.0, a Debian based Linux OS, which is rock-solid stable, very responsive and has excellent Windows compatibility.