That's interesting. Usman is the resident IIS expert. Maybe he will be kind enough to address the question/issue. For that matter, anyone @Moodle.org would be nice.
Am kinda surprised at the response from Bitnami, however, but maybe I shouldn't be. It seems to me that one could run the Bitnami stack for solr ... which is apache only ... on the same server as IIS (that uses port 80 and contains the moodle code) .... the Bitnami stack with apache and solr would run on port 8080.
Yep, that would be a rather complicated setup and a challenge for experienced IIS server admins as well (I imagine).
'spirit of sharing', Ken