Add a handler mapping for .ashx
  1. Open IIS Manager: Click on Start > Run > type in "inetmgr" without the quotes
  2. Click "OK"
  3. Expand Sites
  4. Click on either the FAWeb7 or Netclassroom virtual directory
  5. Double-click Handler Mappings on the right screenHandler Mappings
  6. Click "Add Script Map" on the right side
  7. Type in "*.ashx" without quotes in the "Request path" field
  8. Click the browse button in the "Executable" field and browse to "C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll"
  9. Type in "SimpleHandlerFactory-ISAPI-2.0" for the "Name"Script Map
  10. Click "Ok" and then close Internet Information Services manager

If you encounter the following error: The specified module required by this handler is not in the modules list. If you are adding a script map handler mapping, the IsapiModule or the CgiModule must be in the modules list, then ensure that you have installed the required IIS7 components.