Why Don't Windows Updates Install?

This is a known problem (known by Microsoft).

One of the workarounds is to disable (temporarily) any firewall or antivirus software you have running and try again. This seems to be a particular problem with F-secure and McAfee products.

Microsoft have a page that describes this. It is a little technical but stick with it and it may help: "You cannot install updates from Windows Update".

The next solution is also from Microsoft and is really techie! Windows Update Not Working. 

If this doesn't help you then you canget free support from Microsoft. You give them details of your problem on this page:

https://support.microsoft.com/oas/default.aspx?gprid=6527&st=1