For years I've used (and registered) a little utility called Visual CHM (or VisualCHM). It just made my life slightly easier in creating CHM files. It never cost much and worked well. Fortunately I have a backup copy because the owning domain is now gone! The product had not been updated in years, so it isn't surprising, but is sad to see.
Naturally, some cyber-squatter grabbed the domain and filled it with ads, so I won't mention it. It is the same thing that happened to me years ago when I lost a domain due to negligence.
Thanks to the WayBackMachine (gotta love it, please support the Internet Archive) this site is still available. Many corporate site owners disallow its robots, but small businesses like mine encourage it! It gives our users a history of where we've come from and what we've done.
So, here you go for anyone looking for Visual CHM. The entire site AND downloads are archived by the Internet Archive here:
Of course, you can only get the trial... as for registration, I do not know what you can do ;o. Still, the trial is usable if I recall correctly, at least for a period. Maybe someone can find the author and see if he still has any registration page, if anyone cares anymore.