As long as you mean webhelp when you say HTML Help, it is compatible with Chrome. The issue is that it will only work in Chrome provided it is on a webserver rather than being installed on a local drive. Webhelp is intended to be on a webserver so that is not unreasonable.
You can make webhelp work locally in a way that may be acceptable internally. That will be a matter for your IT people to rule on. See Snippets on my site. Obviously as you are by-passing what Google believes is security protection, it is at your own risk.
See www.grainge.org for RoboHelp and Authoring tips
This is a .chm file, right? Probably depends where it's located. You may have to have Chrome users set their shortcuts to launch Chrome with the "-allow local file access" command line turned on (same as with WebHelp). Chrome did a "security" upgrade last year that knocked out all local html pages.
Thanks, Peter.That is probably the problem. When I switched to RH9, I had people test a version I put on a local drive.
And yes, I do mean WebHelp.
Jeff, sorry I wasn't clearer. It is a WebHelpOnline file, not .chm. Peter provided an answer that is probably right. I need to test it on a web server.