HP ROM-Based Setup Utility - Manual (Page 166)

USB External Port Capability
The USB External Port Capability option configures the USB external ports to operate at USB 1.1
or USB 2.0 speeds.
Select USB 2.0 for improved performance if using an operating system other than Microsoft
Windows Server 2003 or Microsoft Windows Server 2003 x64.
NOTE: Running external USB ports at USB 2.0 with Microsoft Windows Server 2003 or Microsoft
Windows Server 2003 x64 causes delays during installations.
This selection does not affect the internal USB port or USB iLO Virtual Media devices.
166 RBSU menu-driven interface, version 2.xx (G5 and earlier servers)