I just wanted to comment on your thread above (

I installed the latest Windows version 2004 update a couple weeks ago. Yes, it installs the "new" broken JET .dlls, both labeled version 4.0.9801.24. But before installing the update, I had changed the Date Modified of each good working file (msjet40.dll and msrd3x40.dll) to the date of my planned update install. That didn't prevent the good .dlls from being overwritten with the newer bad ones.

So I replaced them once again with the good old files, only this time I changed their Product version/File version numberss to the current version number ...24. Now I'm waiting for another KB update to see whether a new update will replace those good files with the bad ones again. There has to be some cue that the update takes in order to know if it has to install new files - perhaps the version number is that cue.

In the meantime, other than this wrinkle, Windows 10 (2004) is working well for me.