With this feature embedded in Windows 10, you can fully control the apps by blocking non-Store apps or allowing Windows 10 to install apps from third-party platforms. This feature continuously exists in all of the following versions of Windows 10 - 1703, 1709, 1803, 1809 and the latest Windows 10 OS. With the final rollout of Windows 10 Creators, this new feature is able to warn and block users whenever they attempt to install an app from unknown resources outside the Windows Store. Microsoft firstly tested the feature of preventing non-Windows 10 Store apps to install on PC in February 2017 and added it into Windows Insiders on March 20, 2017. To resolve this problem, you can first follow this page to learn some background information and disable or enable Windows 10 to install non-Store apps with provided solutions here: Background When you receive a pop-message, warning you that 'You can only install apps from Microsoft Store' or 'The app you're trying to install isn't a verified app from the Store', like the blow listed image, it doesn't mean that you can only do as what your PC told you.
