It sounds like the root of the problem is that whatever server the help is being viewed from must be UTF8 enabled.
I have previously posted this in response to other similar questions. Hope it helps you. You will need your IT admin people to deal with this.
This is what I was advised by the company hosting my site.
"I would therefore conclude that the solution to this problem (on Linux systems running Apache) is to add the AddDefaultCharset utf-8 directive to either the Apache config or the site .htaccess file. The advantage of the latter is that it only affects individual sites. The default Apache character set is taken from the locale file on Linux and defaults to iso-8859-1. It is the conflict between the Apache header with iso-8859-1 and the page character set of utf-8 that obviously causes Firefox a problem."
In a forum post Chrissy_Tissy added
My machine is Windows, but this fix still worked - some notes about making the fix visible:
1. Do the fix itself (httpd.conf: AddDefaultCharset utf-8).
2. Restart the box to apply the fix.
3. Once the box is restarted, clear your cache in FireFox to make sure you don't continue to see the cached file.
Once all this is done you will see the output content as expected.
See www.grainge.org for RoboHelp and Authoring tips
I forwarded your response to the administrator of Perforce and to the developer complaining of the problem.
This could mean that the installation procedure for my company's software may have to be modified to accommodate the webhelp character set. I am not sure if they want to implement that. When I switched over to RoboHelp, I had to make sure to name my default files wwhelp.htm because the previously generated help were created by FrameMaker files processed by WebWorks Publisher so that developers would not have to make the minor change of having the Help button invoke a new Help file name in order to open online Help.