How do I stop Windows from installing applications on update?

Solution 1:

It will not happen again since Microsoft has stopped installing the previously uninstalled apps with each upgrade in the latest Windows Insider builds. So when you'll be upgrading to Windows 10 Creators Update which should come in March 2017, the apps such as Farmville will not be installed again.

Solution 2:

There are a number of tools such as O&O ShutUp10 that separate some of the Windows 10 settings, providing control over discrete functions such as updating Windows OS and MS applications.

Use any such application with caution... check the app at VirusTotal before use, and back up the OS drive, lest a change make the computer unusable.