Spot on
The most annoying thing on Windows is with automatic updates. It goes and downloads something and pops up an alert at some random time. If you're typing something at the time and just happen to be hitting enter, it's always "yes, do shut down my machine, ignoring any unsaved work that I have, and while you're at it, why don't you make the machine unusable for the next 20 minutes". Aaagh.
Also, speaking of UI components that jump around the place for not good reason, whoever designed the UI for Netflix in a browser deserves to be shot. Stop fucking moving shit around when I mouse-over on it!