Asus P5RD2-VM - Manual (Page 64)

2-18 Chapter 2: BIOS setup
USB Controller [USB OHCI + EHCI]
Configuration options: [Disabled] [USB OHCI] [USB OHCI + EHCI]
Legacy USB Support [Auto]
Allows you to enable or disable support for USB devices on legacy
operating systems (OS). 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]
USB 2.0 Controller Mode [HiSpeed]
Allows you to configure the USB 2.0 controller in HiSpeed (480 Mbps) or
Full Speed (12 Mbps). Configuration options: [HiSpeed] [Full Speed]
BIOS EHCI Hand-off [Enabled]
Allows you to enable support for operating systems without an EHCI
hand-off feature. Configuration options: [Disabled] [Enabled]
Do not disable the BIOS EHCI Hand-Off option if you are running a
Windows ® operating system with USB device.