Thanks, I resolved the problem myself - the simple solution may be useful to others who encountered the same fault First I turned off the firewall and made sure it wasn't set to switch back on when I re-booted. I re-booted and went to settings/windows update/choose how updates get installed.  It was set to download and install automatically, but of course the downloads were not installing automatically - I changed this to "download updates but choose whether to install them" and applied the change. Then I went to "view details" and was able to select all the uninstalled downloads, which I did and they installed. I then rebooted no ;more warning of uninstalled updates and Win 10 started to download and install.
I have a new Dell XPS 13 that came with Windows 8.1.  When I switch on I get a notification that windows updates are ready to be installed.  When I go to settings/update and recovery/Windows Update all I see is the little spinning wait symbol (for hours).  I also recently took up the subscription to McAfee anti virus which came pre installed on the computer.  When I try and open McAfee Central the same happens.  These problems also occur when my McAfee firewall is turned off.  I'm not sure if these problems are related I am concerned that because of the updates not working I won't be able to get my Windows 10 upgrade, I reserved it some time ago but as of today I haven't received my notification. How can I solve these problems?
Windows 8.1 update won't work