every time I get to Loading screen my mouse speed goes down

and I don't mean the in game setting, I have to alt-tab and go to windows setting and fix it there. it started right after my friend logged on his account on my laptop and played a game with it. all his key bindings and other settings where transfered witch is understandable, but changing my windows setting every time I start a game is not cool. I don't even think league of legends should have the access to my windows setting in the first place so please if you know how i can fix this let me know down below.
Report as:
Offensive Spam Harassment Incorrect Board