Recently my wife's laptop started downloading a Windows 10 update. This knocked her machine out when she was waiting for an important email. Yesterday the same thing happened to my laptop when I was preparing documents for a meeting. This morning my tower started downloading a Windows 10 update which tied it up for over an hour. We did not request or want to upgrade to Windows 10. It is bad enough getting reminders pop up every day without it making the decision for you. How can we stop it happening ?