Johnny,
Being a Country fan I'm pleased to see you're alive and well. :)
Thanks for validating my submission, that is, lending support. The advice of using aspnet_regiis -i as it would be used on Windows 7 also doesn't work for asp.net 4.5 (and possibly 4.0) because these MUST be configured in IIS.
So, it is no surprise the other post contributors offered that solution. And from an XP, Windows 7 perspective they're 100% right. I can imagine their being perplexed at my replies that this didn't work.
It all changes with Windows 8. I wonder why, when Visual Studio is installed and thus the latest .Net binary comes with it, why IIS 8 doesn't just get updated? I'd imagine it is a security issue. OK, so have a dialog pop up during VS 2010/2012 install asking if ASP.Net 4.x or whatever future version should be installed? The end user selects "Yes" and doesn't run into these difficulties. Or, just make it part of the pre-install selection of options to update IIS with the latest .Net versions and we're good to go.
Obviously, someone installing Visual studio 2010 Pro or above KNOWS they need this so ... how about someone making the msi packages or web install packages know it also?
But this is for a non-DNN area.
Again, thanks for getting back. I hope others find all this info useful.
Best,
Mike