So I decided I would try out Zend Server CE. I have tried the installation on a server running Windows 2003 and XP Professional with PHP already installed using ISAPI. The install goes fine, but when I try to access the web page I get an FastCGI Access Denied error.
I have tried everything I can think of, including the suggestions on the web for changing permissions on several directories, but I still cannot resolve this issue. I am going to try and get it working but if anybody has any suggestions please let me know.
UPDATE: I was finally able to get Zend Sever installed. I had to remove IIS using add/remove programs, re-install it, then install Zend Server. I like it a lot.