Dude… This is not the option for mouse acceleration. It is actually just what it says and it just improves your pointer precision. If you make a tutorial, know what you are talking about. Now a lot of people are set on the wrong foot.
To really turn off mouse acceleration download mousefix, it changes a registry and after reboot the mouse acceleration is off.
This means that no matter how fast you move your mouse along the mousepad, the distance you move on your mousepad will always be the same distance on screen. Which improved your muscle memory aiming by a lot in the long run.
It is strange, I thought it was something advanced. When I had the settings window for mouse options maximized, the "additional settings" option did not show. I had to scale down the options window to make that option appear…… Thx, for the help anyhow.