Every window has oversized borders, i tried to go to the border settings already, but im at the minimum border size now: 1, but they are still 10px wide!
How do i get it even thinner?
The Border Padding setting is under the Personalization/Window Color/Advanced appearance settings.
This window will pop up. Open the drop down and select Border Padding.

Are you sure you are selecting Border Padding and not Active/Inactive Window Border, because it should go down do zero, although it is still visible at that setting?