Dell Latitude 9430 2-in-1 Service Manual page 88

If Block Boot Until Cleared is set to OFF, select Continue to boot up normally or BIOS-Setup to clear the alert.
NOTE: If Continue is selected, the user will continue to see the alert each time the system is powered on until the alert is
cleared.
To clear the alert, select ON in the Clear Intrusion Warning field in the Security sub-menu of the BIOS setup menu.
88 BIOS setup