Yesterday Microsoft released a new version of .NET Framework, 4.7.2 and it’s showing up as an important update in Windows Update.

For Exchange Servers it’s important that you don’t install this update as this version, at this time, is not part of the support matrix for Exchange Servers:

The full list of supported .NET Framework versions are available at Exchange Server Supportability Matrix – Microsoft .NET Framework

To block the installation of .NET Framework 4.7.2 from Windows Update, you can run the following command:

This will add the following registry key:

To unblock the installation, once it’s supported you can run the following command:

This will remove the registry key from the computer and the update will be available once again from Windows Update.