Hi kemical, thanks for reply, the one PC that's stuck on 28% has been in that position for at least two days, I would have thought there should be a way to cancel it and start again, but I can't find if there is one. I will try it again tomorrow and switch off the AVG first and see if it helps. I rather suspect it won’t but it's worth a try. I can’t get access to it till tomorrow so will get back to you.
I am a little puzzled about the version 1511, Is Microsoft holding this update back for a certain time? I updated three of my computers during November/December 2015, why have my three PCs only just updated to 1511 when it was released back in November 2015?