Image::Magick is notorious for build and runtime errors on windows. It is possible to build it (I did it), just prepare to use the best of your creativity.

installed Windows version of Image::Magick, but none of the suggested hacks I tried allow the httpd.conf to 'see' the Windows Image::Magick

I'm not sure what hacks are needed for testing whether a module works or not. Usually it is really easy:

perl -MImage::Magick -e 1

If that works, your problem is elsewhere.