This is occuring after a fresh install of IIS, and the cfadmin website is configured via WSCONFIG. I followed all the user permission recommendations from Pete's CF11 Lockdown Guide with the exception of the IIS configuration(still haven't removed handler mappings and haven't added any URL deny sequences under Request Filtering). Which eventually I will because that's the goal.
This is what I get after I submit my username and password. the last http request that is made is to /CFIDE/administrator/enter.cfm, which responds with 405.0 Method Not Allowed (invalid method http verb)
After I can keep going back to the login page with no problem. I'm accessing the cfadmin on Internet Explorer logged in as an administrator user of the web server(2012) itself.