Mailbag: How to revert to older versions of the .NET Framework 4 family

Question:

I recently installed the .NET Framework 4.6.1 but ran into a compatibility issue with an application that I’m trying to use. How do I revert back to the .NET Framework 4.5 on my PC?

Answer:

All versions of the .NET Framework 4 family are in-place upgrades, which means that they replace previous versions of the .NET Framework 4 family instead of installing side-by-side.

When installing redistributable versions of the .NET Framework 4 family, that means that you must use the Programs and Features control panel to uninstall the newer version and then re-install the older version afterwards.

However, some versions of Windows include a version of the .NET Framework 4 family as a part of the operating system. On those versions of Windows, newer versions of the .NET Framework 4 family will be installed as OS update packages, and they must be uninstalled using the Installed Updates control panel.

This can be tricky because the OS update packages do not include .NET Framework in the name, so you need to know the KB number in order to find and uninstall newer versions of the .NET Framework 4 family, or if you know when you installed the newer version of the .NET Framework, you can sort the Installed Updates control panel by installed date and find it that way.

Some of the download pages for the .NET Framework 4 family also include information about which exact KB number will be installed on which versions of Windows. For example, if you go to the .NET Framework 4.6.1 download page and expand the Additional Information section, it lists the following:

When you install this package you will see following packages/updates installed as per operating system:

  • On Windows 7 SP1 / Windows Server 2008 R2 SP1, you will see the Microsoft .NET Framework 4.6.1 as an installed product under Programs and Features in Control Panel.
  • On Windows 8 / Windows Server 2012 you can find this as Update for Microsoft Windows (KB3102439) under Installed Updates in Control Panel.
  • On Windows 8.1 / Windows Server 2012 R2 you can find this as Update for Microsoft Windows (KB3102467) under Installed Updates in Control Panel.
  • On Windows 10 you can find this as Update for Microsoft Windows (KB3102495) under Installed Updates in Control Panel.