Having trouble getting MVC working on IIS6? This article will get you through all those problems.

http://haacked.com/archive/2008/11/26/asp.net-mvc-on-iis-6-walkthrough.aspx

1. Made folder in IIS an application in the Directory tab. (right click folder -> properties)
2. On the same tab click the configuration button
3. Check to see if there is an app extension mapping for .mvc
4. If not, click add
5. The executable path should be: C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll (the path might be slightly different on your server…you just have to find that dll and reference the path)
6. Make sure to uncheck “Verify that file exists”
7. There needs to be a wildcard inserted for the above dll
8. If there isn’t, click insert. Use the same path we used in the mapping. Again, make sure to uncheck  “Verify that file exists” MVC app should route properly now.