In my previous post, I outlined how to get Auctex to launch Acrobat Reader. Here's a minor change based on the same poster's advice. If the reader is the default application to view pdf files in Windows, you don't even need the acrord32 in the configuration. Just

TeX-output-view-style is a variable defined in `tex.el'.
Its value is
(("^dvi$" "^pstricks$\\|^pst-\\|^psfrag$" "dvips %d -o && start \"\" %f")
("^dvi$" "." "yap -1 %dS %d")
 ("^pdf$" "." "cygstart %o")
("^html?$" "." "start \"\" %o"))

is enough.