BIOS settings are for using USB mouse/keyboard in dos environment.
turned off windos detects mouse keyboard and doesnt use settings.

I figured that but most people today are far from using dos. This is
especially why I think the description is misleading - should rather be
something like "Only activate if your OS does not recognize
mouse/keyboard" or something even more dos-specific.
Anyway, I learned my lesson ;-).

Matthias