When Windows updates routinely override existing settings and break existing setups, they fit my definition of malware. Windows 10 qualifies fully and I wish I had never applied the update on one machine last summer. I know several people who applied the update and only one of them is happy with it (as of a few months ago, it is not topic number one).
Microsoft seem to think we bought our PCs so we could run Windows Update and glory in its magnificence. No, I bought mine to perform certain functions and installing Windows 10 has broken more than it alleviated. It is not the security features which annoy me, even the telemetry is a lesser irritant. What really annoys me is when an update leaves something utterly broken, and the knowledge that the next update is going to repeat the experience.