Two ideas: use the recovery option: Press and release the Power button to turn on the operation system. Press “-“ to enter into GIGABYTE System Recovery. Use Directing Hot Key to operate GIGABYTE Smart Recovery.
Or, if not working, try using V Lite for slpstreaming the needed drivers into the Windows 7 installation kit.
Alexoiu and Dodger46, thanks for your replies. Before trying your solutions, I found that the USB port that the keyboard connects to was visible during installation but that the other USB port is not. Managed to get up and going.
Thanks again for your help