For a couple of weeks now, I have been trying to download and install Windows Update KB4093118 (April 2018 Security Monthly Quality Roll-up) on my Windows 7 Professional (64-bit) PC using “Windows Update”. Every time, it has ended in a “failure” with error code 80072F78. The failure would always occur during the downloading stage of the update at the 45% downloaded mark.The Fix: Simple, all I had to do was disable protection in my anti-virus program, which in my case happens to be Bit Defender (free version).
Being that I never had this problem with other updates to this point, I didn’t think to do this. I guess some antivirus programs mistakenly think that some Windows Updates as “malicious” and block the downloading of these updates as a result.
So if you ever have a problem downloading or installing any Windows Updates on any Window operating system, your first attempt at resolving the problem should be to disable any and all anti-virus and anti-malware programs you have running and protecting your PC.
I hope this helps someone else because Google search results on how to solve this issue of Windows Update KB4093118 (Security Monthly Quality Roll-up for April 2018) with error code 80072F78 were of no help to me, not even Microsoft’s own support thread links.