Have you been running any registry cleaners lately as they can cause major issues, or have you had any malware infections? If you've had the latter see the last link in my signature below.
Also are you running any other security software?
You do have control over McAfee and you can control when it updates if you wish, however I don't recommend that as it will cause reminder popups.
Try running the Virtual Technician to see if it finds and fixes any problems. If not......
I suggest you try uninstalling the software via Control Panel > Programs and Features, then run the MCPR cleanup tool and reboot, then reinstall from your online account.
By the way, exactly what was that Windows Update? It should be listed in Update History.
It will be more helpful if you could post the KB number of Windows Update that was recently installed. To view the latest installed updates
Open Control Panel\Programs\Programs and Features > Select View Installed updates in the left pane > Check the KB number for latest Successful update and post back..!