Occasionally the Search mechanism stops working in Microsoft HTML Help (.CHM) files.
This article is intended to assist in correcting this issue.
MJ's Diags is an application offered by HelpWare. (HelpWare is the company that created, maintains and sells FAR (Find and Replace)). Click here to visit the HelpWare download site. There is no charge to obtain and use the MJ's Diags file.
MJ's diags downloads as a .ZIP file. Unzip it and run the EXE inside.
Click the MJ's Diagnostics button followed by Generate Diagnostics Report.
Your browser will then present a report.

This is often sufficient to correct the issue.Re-compile any affected .CHM files and test.
Uninstall the Microsoft HTML Help Workshop (HHW). Download and install the latest version of HHW. Click here to visit the Microsoft download page.
When you install HHW it will probably present a message advising you that your computer has a newer version of HTML Help. Don't sweat the message. Just acknowledge it by clicking OK.

Re-compile any affected .CHM files and test.
This article was composed by Rick Stone. He is known by the following names in the Adobe support forums. (RoboWizard and Captiv8r)
Rick has been using RoboHelp since version 2 back in the last century (1992). He has been using Captivate since before it was known as Captivate. He is an active participant in the Adobe Support Forums. He is an Adobe Certified Expert, Adobe Community Expert, Microsoft Help MVP and is on the Adobe RoboHelp and Captivate advisory boards. Rick earns his living by facilitating Adobe RoboHelp HTML and Adobe Captivate classes and selling materials related to each of these products.

This work is licensed under a
Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License