ASP.NET 2.0 and ASP.NET 3.5 require the ASP.NET 4.5 feature to be enabled on a computer that is running Windows 8 or Windows Server 2012. If you remove or disable ASP.NET 4.5, then all ASP.NET 2.0 and ASP.NET 3.5 applications on the computer will not run.
To enable the ASP.NET 4.5 feature in Windows 8 or 8.1, follow these steps:
Press the Windows logo key, type control panel, and then click the Control Panel icon.
Note If you are not using a keyboard, swipe in from the right edge of the screen, tap Search, type control panel in the search box, and then tap the displayed Control Panel icon.
Click Programs, and then click Turn Windows features on or off.
Expand .NET Framework 4.5 Advanced Services.
Select the ASP.NET 4.5 check box.
For information about how to enable the ASP.NET 4.5 feature on Windows Server 2012, go to following Microsoft IIS Learning Center website: