In response to wmcole. I had been on 2004 since last October when it auto updated itself, 20H2 showing as an option. Did not update, left it there as an option. June 5th first boot of day, noticed lot of disc activity, Task Manager showed Windows Module installer running. Finally request to restart, found I had been updated to 21H1 thereby leap-frogging 20H2. Time taken to complete was not that long, did not notice any differences in appearance, running etc. I was holding on updating to 20H2 as according to MS there were fundamental changes to the workings, main concern was that the traditional Control Panel was in effect, disappearing. Still available as it has been for years.
In response to MarcHoppe. Wednesday, 3 minutes after AM boot, notification that I needed to restart to install update. This was KB5004945, the MS FIX referred to. Installed as no choice. Went into control panel to check if Restore Point had been created, RECOVERY icon had moved on a place, noticed there was now an item for FLASH Player. Half hour later, BLUE SCREENED when in an EXCEL worksheet, auto restarted, up & running again. Event Viewer log entry under error listed 'BUGCHECK'. Couple of hours later another BLUE Screen again, I was just about to open File Explorer from Task Bar, auto rebooted again & running, EV showed another BUGCHECK error. Ran FP normal uninstaller, ran but FP still in Control Panel. Ran MS Catalog FP uninstall, came up with as already installed so FP still in control panel. Removed KB5004945 thru' uninstall updates, FP still there although no more blue screening after, well at least for the next 3 hours. Spoke to my computer guru, suggested doing a System Restore, done that, FP now gone from Control Panel. I then halted further updates till after the next patch Tuesday. Touch wood, no more BLUE SCREENS since. MS seem to completely lost the plot now, looks as though released this update in a panic, and once again, did not test before release. What we really need is a way of halting updates on a permanent basis