The method outlined by user683780 (manually d/l KB3173424 and KB3172614 etc) worked for me.
Be sure to disconnect your computer from the internet before running these files, otherwise they will not install - your computer will look like it is installing the first one but in fact it is still trying to use the old version of windows update already installed.
Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Other company and product names may be trademarks of their respective owners.You can run the tools listed below in Safe Mode with Networking, although they might then tell you that problems were not fixed.Windows 8 (not 8.1) stopped receiving updates after 12th of January, 2016.How you'll upgrade depends on which version of Windows you're upgrading from. Windows 8.1 is a bit different from previous versions of Windows in that people generally get it through an upgrade from the Windows Store.Luckily, Microsoft allows you to download a legal Windows 8.1 ISO file, so you can make your own Windows 8.1 installer disc or USB drive.