Regenerate help tags automatically on save (Windows)

C:\Program\ Files\ (x86)\Vim\vim82\

is off-limits. Whatever you do to customise Vim should happen in:

C:\Users\BobMorane\vimfiles\

In this case, your file should be there:

C:\Users\BobMorane\vimfiles\doc\myHelp.txt

and your autocommand should look like this:

autocmd BufWritePost ~/vimfiles/doc/* :helptags ~/vimfiles/doc/

You can use UNIX conventions within Vim: ~ is always the user’s “home” directory and / can be used no matter what platform you are on.