I already called Apple Care about this and they have no solution. My Caps Lock will not remain disabled! I have now disabled it for the fourth time in the past ~ one week. System preferences/Keyboard/ keyboard tab/ modifier keys button 1st choice of the four is caps lock. I change it to “no action.” I click "OK" Caps Lock is off and does not work but, within 2 to 3 days… it's back working again!