How do I install 5.4.3.x WITHOUT REBOOTING under windows ?

LibreOffice uses Windows Installer (MSI) technology (a Windows OS component). That component performs checks if it can replace required files when installing. If it cannot, a reboot is required.

Sometimes it may give false positives. Unfortunately, this cannot be detected by LibreOffice. Also, recently we had included into installer support for another technology of Windows, called Restart Manager (which is intended to try to restart programs that block the files, and so avoid requirement to restart computer).

But - well… it all isn’t a sure remedy. So sometimes the installer still asks for reboot. And from my own experience, most of the times, you can just safely ignore the reboot, and continue using the upgraded LibreOffice without issues. LibreOffice uses only a few components that might be used by other programs - mainly the Explorer extension that displays information about ODF files in the Explorer, and using older version of the DLL (until you reboot sometime in the future) generally doesn’t hurt. This isn’t an “official” advise to ignore the reboot prompt, it’s just my own point of view based on experience.

Tanks Dude! Beauty of an answer.