Originally Posted by kneeken
......computer won't download its driver in bootloader mode.....
With device connected to PC.
> Computer/This PC (Wins 8.1) > right click
> Device Manager
> Other Devices > sub Menu
> Android > right click
> Update Driver Software
May be better to ask in another XDA forum.
(Hope I'm not breaking any Forum rules by my suggestion to elsewhere, if so please delete as appropriate, am just trying to help)