Dell Latitude 5420 Owner's Manual page 243

USB Allows you to
Emulation enable or disable
the Legacy USB
Emulation.
Default Setting:
Enable Legacy
USB Emulation is
selected.
Fn Key Allows you to set
Emulation the option where
the <Scroll Lock>
key is used to
simulate the <Fn>
key feature.
Default Setting:
Enable Fn Key
Emulation
POST Allows you enable
HotKeys the sign-on screen
message display
indicating the
keystroke
sequence to access
the System Setup
option menu.
Default Setting:
Enable F12 Boot
Option Menu
Fastboot Allows to set the
option to speed up
the boot process.
The options are:
Default Setting:
Thorough
Minimal
Thorough
Auto