Using BIOS 0021 reset to defaults (F9). Then, following your instructions for Win 7 Installation.
When USB 3.0 (XHCI mode) support is set to enable as your instructions say, my usb 2 mouse/keyboard connected to the rear ports is not active..
I can change USB 3.0 (XHCI mode) setting to disabled which enables my mouse/keyboard.
Are your instructions incorrect or do I misunderstand something?