You could download and tweak the source for the mingw download.  I think 
:)

http://www.akitaonrails.com/2008/7/21/testing-the-new-one-click-ruby-installer-for-windows

http://www.akitaonrails.com/2008/7/26/still-playing-with-ruby-on-windows

http://rubyinstaller.rubyforge.org/wiki/wiki.pl?Mingw

Those talk about how to compile it with mingw.
With MSVC I'm not sure how :)

Good luck.

-R

Ronn Ross wrote:
> Hello all,
> 
> I'm running Ruby on windows xp. I made changes to the keywords file and
> would like to recompile the Ruby source to see my changes. How do I
> recompile Ruby source on windows?
> 
> Thanks in advance

-- 
Posted via http://www.ruby-forum.com/.