There has been a controversy, recently between Microsoft and antivirus vendors: Kaspersky Lab reported Microsoft to the Russian Anti-trust agency. The accusation? Boycott third-party antivirus software in favor of Windows Defender, the made-in-Redmond antivirus.
Things are, of course, a bit more complicated than that. With Windows 10 Creator Update, Microsoft may temporarily disable antivirus and other security products if they are deemed not compatible with the upgrade. If developers release a new version of the software, the problem would be solved, according to Microsoft. Waiting for this upgrade, Windows 10 turns on Windows Defender to avoid letting users unprotected.
This would be a good thing for users, but Kaspersky replies that Microsoft’s technical support told users that Windows 10 does not work on third-party antivirus and other security products, period. This answer, perhaps given by a not so prepared customer assistant, might be a thorn in Microsoft’ side.