I am having a similar problem -- I can't get Apache to execute php scripts even after carefully modifying httpd.conf to locate the right modules, etc.
Apache initially burped on mod_php files (which I can't find installed anywhere, either), so I commented the lines referring to mod_php out, but it still didn't seem to do anything.
I'm not getting an error, just blank web pages and raw php code in the html files when I "view source." It has to be that httpd and php are not communicating.
Anyone have any thoughts on this?