Hi Clive,
I had some issues with the drivers for the Chuwi Hi8 also. My main issue was for the touch screen though. No matter how many times, or different ways, i reinstalled them the touchscreen was always off.
I had to reinstall using the Chuwi Hi8 Windows 8.1 package and follow the translated Chinese installation Guide. You need two thumb drives and a keyboard hooked up to an OTG cable for the process though.
After that I upgraded to Windows 10 and all worked again.
The Guide and the original Windows 8.1 image are provided on this site by Chris 🙂 :
http://techtablets.com/downloads-drivers-roms/
As for the OTG cable I use this one:
http://www.amazon.com/gp/product/B00U90AM04?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00
It charges and allows OTG functionality at the same time for me. I believe you need to use position 2 for it.