There are several issues that can arise while running Windows Updates. Microsoft has a great tool called the "Windows Update Automated Troubleshooter" that actually works well to diagnose and repair some of these issues.
One example would be:
-Windows Update running constantly, "Checking for Updates", without making any progress.
Try running the Windows Update Automated Troubleshooter from here:
https://support.microsoft.com/en-us/gp/windows-update-issues/en-us
There is also a great Interactive Guide that will walk you through, and ask questions about the Windows Update issues you are having, what specific error codes you are getting, and help you to diagnose the issue:
https://support2.microsoft.com/common/survey.aspx?scid=sw%3ben%3b3779&showpage=1