Setting up a new development box for myself I had forgotten all about the necessity to use theaspnet_regiis.exe –i  command. The information is fairly easily available, but with this post I’d like to cut away the fat and stick to a very easy how-to.

On my Windows 8.1 aspnet_regiis resulted in this message:

Microsoft (R) ASP.NET RegIIS version 4.0.30319.33440 
Administration utility to install and uninstall ASP.NET on the local machine.
Copyright (C) Microsoft Corporation.  All rights reserved. 
Start installing ASP.NET (4.0.30319.33440). 
This option is not supported on this version of the operating system.  Administrators should instead install/uninstall ASP.NET 4.5 with IIS8 using the "Turn Windows Features On/Off" dialog,  the Server Manager management tool, or the dism.exe command line tool.  For more details please seehttp://go.microsoft.com/fwlink/?LinkID=216771. 
Finished installing ASP.NET (4.0.30319.33440).

Googling around a bit more turned up this link that explains how to go to the Windows Features (viaappwiz.cpl) to activate .Net 4.5 on IIS:

Or to run this from an administrative prompt:

dism /online /enable-feature /all /featurename:IIS-ASPNET45

Please note the /all parameter which is not mentioned in the KB article, but necessary to automatically include all the necessary components.

UPDATE:

In order to get my webservices running I have spent more hours on struggling with the IIS beast. It appears that (according to this) you have to have to switch on yet another feature:

Or, if you want to automate all this, more dism commands:

dism /online /enable-Feature /all /FeatureName:WCF-HTTP-Activation

dism /online /enable-Feature /all /FeatureName:WCF-HTTP-Activation45

from：http://phejndorf.wordpress.com/2014/01/10/enable-net-4-5-in-iis-on-windows-8-1/

Enable .Net 4.5 in IIS on Windows 8.1