My ASP.NET (running with .NET 4.0) site is throwing an error.
Error:
The page you are requesting cannot be served because of the ISAPI and CGI Restriction list settings on the Web server.
I’ve tried doing the steps in this article. I didn’t have a CGI/ISAPI option, so I clicked on “ISAPI Filters”. The “Restriction” column seems to be missing.
http://frejnorling.wordpress.com/2011/02/13/configure-iis-7-5-to-manage-asp-net-4-0-web-pages/

You are looking in the wrong place. You have opened the “ISAPI Filters” feature, not the “ISAPI and CGI Restrictions” feature:
Open that feature and you will see the restrictions column.