ASP.NET 4.5 has not been registered on the Web Server

30Nov/155

ASP.NET 4.5 has not been registered on the Web Server

As a .net Developer, I have Visual Studio installed and this (usually) includes its own little version of IIS Express. This is all configured out of the box on install and just works.

After upgrading to Windows 10, I started getting this error:

ASP.NET 4.5 has not been registered on the Web server. You need to manually configure your Web server for ASP.NET 4.5 in order for your site to run correctly.

The usual trick is to go to command prompt, find your .NET Framework directory (somewhere near C:\Windows\Microsoft.NET\Framework\v4.0.30319) and then run aspnet_regiis there.

Unfortunately, on Windows 10, this doesn't work. It'll respond with:

Microsoft (R) ASP.NET RegIIS version 4.0.30319.0
Administration utility to install and uninstall ASP.NET on the local machine.
Copyright (C) Microsoft Corporation.  All rights reserved.
Start installing ASP.NET (4.0.30319.0).
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 see http://go.microsoft.com/fwlink/?LinkID=216771.
Finished installing ASP.NET (4.0.30319.0).

This all makes sense... you instead need to hit the start button, type "programs and features" into the search and then hit the first result that appears.

Once in the Programs and Features window, hit the "Turn Windows Features on or off" in the left pane.

Now scroll down through the tree and find:

Internet Information Services
- World Wide Web Services
  - Application Development Features

...and then check all the relevant features you require. I chose .NET 3.5 and 4.6.

Let it do its work and then you should be back to happy-development-land in VS before you know it. If not, then it could actually be a bug in Visual Studio. Please check the following patches for your version of VS: VS2010, VS2012 or VS2013.

If you could only see .NET 4.6 (or have just updated to it...)

Then you need to patch Visual Studio as per the instructions here. Seems that upgrading to 4.6 won't let Visual Studio correctly see that 4.5 is installed.