You shouldn't have to as there was a previous modification to enable the use of USB keyboards.
I would suggest that you check your BIOS settings and see if USB devices are enabled on boot. It is most likely to be in the Integrated Peripherals section of the BIOS/CMOS but that could be different as there is no standard for the layout, or how to access the BIOS. For me as my system is booting I keep clicking the Delete key (for some it may be the F1 key), and select the Integrated Peripherals from the first screen, or you may have to go looking.
I don't know if you might have to have a ps2 keyboard to do this.