Stuck trying to reinstall Emacs 23.0.92 and setup dying each time

I had set up Cygwin yesterday with the experimental Emacs 23.0.92.  I
had done other updates after that, forgetting the fact that since I'm
using an experimental package, I have to set the Emacs-related pages to
"Keep".  I'm now in a state where I have the 23.0.92 executable, but
with /usr/share/emacs/21.2.  So, now I'm trying to run setup again to
reinstall 23.0.92, or uninstall it, or anything.  No matter what I do,
setup dies hard, requiring a forced kill from task manager.

What can I do to clean up from this situation?

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple