[AUCTeX] automatic package search fails

[Sivaram Neelakantan]

Hi,

On a XP machine, I configured and installed CVS auctex thus.

./configure --with-emacs=/cygdrive/c/gnu/emacs-23.3/bin/emacs
--with-texmf-dir='/cygdrive/c/MiKTeX2.9'
--prefix=/cygdrive/c/gnu/emacs-23.3
--with-lispdir=/cygdrive/c/gnu/emacs-23.3/site-lisp

With a minimal file as
--8<---------------cut here---------------start------------->8---
\documentclass[usenames,dvipsnames]{beamer}
\begin{document}
\begin{frame}
  \frametitle{temp}
  blah
\end{frame}
\end{document}

%%% Local Variables: 
%%% mode: latex
%%% TeX-master: t
%%% End: --8<---------------cut here---------------end--------------->8---

If I try to add a package via C-C RET, the \usepackage prompt appears
but I get the error message

Searching for files...
TeX-search-files-by-type: No TeX trees available; configure
`TeX-tree-roots'

which I see is in tex.el.  It says that the following should be set?

$TEXMFHOME" "$TEXMFMAIN" "$TEXMFLOCAL" "$TEXMFDIST"

I'm not sure whether it's set at all as I use Miktex.  And I don't
 remember explicitly setting this at all manually anytime before when
 I installed/used auctex.

And the minimal example is erroring out 

--8<---------------cut here---------------start------------->8---
LaTeX Font Warning: Font shape `OT1/cmss/m/n' in size <4> not available
(Font)              size <5> substituted on input line 6.

! Undefined control sequence.
address@hidden address@hidden address@hidden@end 
                                                  address@hidden 
l.6 \end{frame}
               
! Undefined control sequence.
address@hidden address@hidden address@hidden@end 
                                                  address@hidden 
l.6 \end{frame}
--8<---------------cut here---------------end--------------->8---

What should I do to fix this, please?

 sivaram
 --