I didn't write this system so I don't really know what is going on.
I installed a new version of Visual Studio and something (I have no clue what it could be) might have changed because now when I try to set up a site it's just giving a 404.0 referencing the .dll.
The ISAPI .dll manages requests for the application so that is how pages get served up. If I make a test site with just index.htm in it the site works. But the mere act of putting the ISAPI .dll in the directory with that index.htm file causes it to start throwing the 404.0...forever. Even if you delete the ISAPI .dll from the directory the error stays.
I'm really confused so any general or vague ideas would still be greatly appreciated.