I have an employee who is the most computer illiterate person I know. Because of this, her computer is separate from everyone else (not networked). She understands her shortcomings, and has on several occasions paid out of her own pocket to have “repairs” done to her machine.
Recently I noticed that every single time she shuts down, there is an update. She took today off, so I just turned her computer on, then shut it down 5 times. Each time I got the note that an update needed to be applied, do not shut down, etc.
Probably an update that Microsoft thinks is ‘important’ is failing to install for some reason, and the update program keeps trying again. I think you can go into into the update history and tell it to give up on certain ones, if they repeatedly fail to install. This is a little insecure (but I think the chances of getting malware just because one security patch is missed is not very high), and may cause problems down the line with later updates that don’t work because the first one is not there, but, short of doing a full Windows reinstall, it is the best you can do.
Don’t give up on it right away though. I have had updates fail, and then succeed and install properly on the third or fourth try. Og knows why.