Asus T4-P5P43 - Manual (Page 90)

5-24 Chapter 5: BIOS setup
BIOS EHCI Hand-Off [Enabled]
Allows you to configure the BIOS EHCI Hand-Off.
Configuration options: [Disabled] [Enabled]
Legacy USB Support [Auto]
Allows you to enable or disable support for Legacy USB storage devices, including
USB flash drives and USB hard drives. Setting to Auto allows the system to
detect the presence of USB devices at startup. If detected, the USB controller
legacy mode is enabled. If no USB device is detected, the legacy USB support is
disabled. Configuration options: [Disabled] [Enabled] [Auto]