These are steps to setup MVC3 project on IIS 5 1. Right click on Default Web Site and click Properties
2. Make sure the website or virtual directory is an Application.
3. Set permissions to Scripts Only
4. Click Configuration. Under the Mappings tab, click the Add button
5. You need to insert the path to the file aspnet_isapi.dll. This is most likely C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll.
6. In the Extension field, enter “.*” (excluding quotes).
7. Select All Verbs. Select “Script Engine”. Make sure ”Check that file exists” is not selected.
8. Here’s the bug. “.*” This isn’t a valid extension in IIS 5.1 so the OK button is disabled. Click in the
Extension field, then in the Executable field, and the OK button should be enabled! Click OK at this point.