This is a repost of a post from an old blog, made on July 20, 2012, that used to be on:
As you may know if you want to map client certificates to IIS 7 for authentication purposes, you must use the editor by default, as described in this blog.
If you want to have the IIS 6 like option of mapping the certificates through UI, you cam checkout this blog, and download the ClientCertificateMapping extension for IIS 7.
After installing the extension you will get new Client Certificates option in the IIS right side window
which will open a window like this one