win sens prob

if i set my win sens 5/12 it's ok fine.

but when i shut my pc and start it again or reboot or w/e it goes back to 6/12

when i set it there is buttons "ok" "cancel" "use"

i have pressed both "ok" and "use" in both orders

and it's fcking dumb that i need everytime set it to 5/12 when i start my pc, in order to make everything else settings work, couldn't care less to change 1000 other settings cuz it won't let me use win sens i like to

i have vista but dunno will that cause it, if u got idea plz help me :)