More information about the versions of the .NET Framework that ship with Windows 8

Since the release of Windows 8 last fall, I’ve gotten a few questions about what versions of the .NET Framework ship with Windows 8 and how to install, uninstall and repair them.  Most of this information is documented in other places, but I wanted to put together a brief summary and post some links to hopefully make this information easier to find.

Windows 8 and the .NET Framework 4.5

Windows 8 includes the .NET Framework 4.5 as a part of the OS.  It is installed by default and it is not possible to remove it.

The .NET Framework 4.5 is an in-place upgrade for the .NET Framework 4, and applications built for the .NET Framework 4 will run if the .NET Framework 4.5 is present.  As a result, there is no need to install the .NET Framework 4 or 4.5 redistributable packages on Windows 8.  If you attempt to run the .NET Framework 4 or 4.5 redistributable installers on Windows 8, they will prevent you from installing the redistributable versions.  See this knowledge base article for more information about this scenario.

Windows 8 and the .NET Framework 2.0, 3.0 and 3.5

Windows 8 includes the .NET Framework 2.0, 3.0 and 3.5 as a part of the OS.  They are not installed by default, and it is possible to add or remove it by using the Windows Features control panel.  There is also an install-on-demand feature in Windows 8 that will prompt you to install the .NET Framework 2.0, 3.0 and 3.5 if you run an application that requires it.

If you attempt to run the .NET Framework 2.0, 3.0 or 3.5 redistributable installers on Windows 8, they will prevent you from installing the redistributable versions.

Here are links with more information about how to install the .NET Framework 2.0, 3.0 and 3.5 on Windows 8:

• Installing the .NET Framework 3.5 on Windows 8 - https://msdn.microsoft.com/en-us/library/hh506443.aspx
• Troubleshooting .NET Framework 3.5 installation errors on Windows 8 - https://support.microsoft.com/kb/2734782

If you have an application that depends on the .NET Framework 2.0, 3.0 or 3.5, here are links with more information about options for automating the installation on Windows 8:

• https://blog.kineticjump.com/2012/08/03/EnablingNet35OnWindows8DuringAnApplicationUpdate.aspx
• https://msdn.microsoft.com/en-us/library/windows/desktop/hh848079.aspx

<update date="2/8/2013"> Added a link to a knowledge base article with more information about scenarios where installing the .NET Framework 4 or 4.5 redistributable package is blocked by Windows 8. </update>