This kind of question is better for the Help and Support forum, but since we're here already:
This is most likely caused by Mouse Pointer Trails and Hide Pointer While Typing enabled while in full-screen mode. The pointer trails are visible as the mouse cursor repeating itself and leaving a trail along the screen. The Hide Pointer While Typing is a feature which makes it easier to see the screen while one is typing. They can both be turned on via the Mouse options control panel (Control Panel -> Mouse) and can be turned off there as well.
If you're still running into issues, always feel free to contact Tech Support directly. You can do so at this link: