Spider is generally recommended to be run on an IIS6 Server, but for those sites wishing to try and get it working on IIS7, then the following may help.
Error 404.3 regarding MIME Types
The error is typically something like:
HTTP Error 404.3 - Not Found Description: The page you are requesting cannot be served because of the Multipurpose Internet Mail Extensions (MIME) map policy that is configured on the Web server. The page you requested has a file name extension that is not recognized, and therefore is not allowed.
Even though a an IIS machine typically has .Net installed, it may no neccessarily have the correct .Net extensions setup in IIS.
See this article  for more details on setting up these extensions in IIS.
The above information is for users of PCSchool Student Management School Software.