LO Version: 5.4.7.2. OS XPSP3 Pentium 3 Celeron
The built-in help is intstalled but system is reports on F1:
“The LibreOffice built-in help is not installed on your computer.”
Mike Kaganski, thanks!
Exactly the built-in help was not available because of mismatch between En (USA) UI language selected in Options
and Russian language of installed help pack. I have uninstalled the Russian language help pack and have installed
En (USA) language help pack. Now the built-in help functions OK.
And BTW I have discovered the alternative - don’t change the help pack, but to change in Options En (USA) UI language for Russian language.
You also don’t need to uninstall one help pack to install another. You may install several in parallel.