Replacing the old winhlp32.exe file?

I have several ancient but still useful programs whose Help file does
not work.(It opens the top level Microsoft Support page!)

I understand from this post
https://www.tenforums.com/general-su...dows-10-a.html
that the fix requires replacing the existing winhlp32.exe file by a new
one, which I've downloaded. But Win 10 requires permissions to be
changed from 'TrustedInstaller' to achieve that. This article explains
how:
https://helpdeskgeek.com/windows-7/w...stedinstaller/

I'm trying to do so, but fail at the step shown he
https://www.dropbox.com/s/bghtvllj8h...LP-1.jpg?raw=1
This is what mine displays:
https://www.dropbox.com/s/4zilyt1qwk...LP-2.jpg?raw=1

How do others overcome this problem please? Or is the consensus to leave
those permissions alone and instead use some second best method, such as
converting the HLP file to CHM. Or even just using a PDF user guide if
there is one.

Terry, East Grinstead, UK