I didn't know much about KB........ update, until yesterday. I was switching off my main PC, going to restart it to then flash my BIOS. But it hung for ages at the "Preparing to configure Windows Update" screen with the swirling thingy and just would not change from that. Eventually, after an hour, I kept my finger on the power button, but then also needed to remove the power to the PC, and managed to reboot it. I then checked for Windows updates and noticed that KB4601319 was part way through the download / install process. That seemed to go on for a long time. Thankfully, after WU claimed to have finished, I then shut the PC down and that same process of "configuring...................." only lasted for less than a minute and it shut down and then started fine.
This has the potential to be fun for our media server in the loft. I have remote access but if it craps out then it is a fun job getting actual access to it.
Happy days, as usual, with WU.