Often I have such an effect, that my mouse cursor slows like it adheres to the surface of the screen. Mouse is optical and surface of the desk if perfect, so it cannot relate with ball dusting. Also, when cursor unfreezes, it catches the distance it forgot to move, so, it is most probably software problem with operating system.
Simultaneously, in task manager, I can't fins any process, that can occupy processor or disk resources.
The the impression is that some program occupies some IO resources, which are not indicated in task manager directly.
Is it possible to track this kind of loading somehow?