Thanks guys,
I gave up waiting and went to bed. After 16 hours I got to 100%. Then another 3 hours waiting while it was churning away before it was usable.
Over 6 hours now and Win10 update still stuck at 92%. Other posts are suggesting a range of fixes, but if you are not tech savvy what do you do? Take it to a tech and pay for a 'repair'.
Not good enough MS!