My PC hangs during boot after installing Libre Office 6.

My desktop PC hangs during boot after installing Libre Office 6, and associated C++.
Just sits there with a black screen and the rotating dots.
I had to reinstall my Windows 10 (Fall Creators) system.

Can’t you boot on safe mode? https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode

I didn’t try to boot in safe mode. The hang occurred early in the boot. I do not want to have to go through the recovery procedure again.

Safe mode should not imply a recovery procedure.