Introduction

The Compiled HTML Format (CHM) from Microsoft has been the standard for Windows help files from Windows 98. The CHM format is based on HTML files, but has the advantage over a collection of HTML files that

• A navigation tree makes it easy to obtain an overview
• It is easy to perform full text searches
• It is possible to collect the information on one topic (multiple pages, images) into one file

Any PC on which Windows 98, Windows ME, Windows 2000, Windows XP, Windows Vista or Windows 7 and Version 4.0 or above of the Internet Explorer is installed should be able to display CHM files.

Notes about using CHM files

With several service packs for Windows and Internet Explorer, Microsoft has changed the handling for CHM files.

If opened CHM files from Beckhoff show a structure tree but no pages, please follow the following notes.

• Load the desired CHM file down and store it to a local drive of your PC (no network drive!), e.g. drive C:\
• Open the local stored CHM file by clicking onto it in Windows Explorer
• If the local CHM file is not able to be opened, click onto the CHM file by using the right mouse button and choose Properties from the shown context menu.
  The following dialog will be displayed:
  
  
   
• On the tab General click on the button Unblock. Now, this CHM file can be read on your PC.