CHM-type 'Help' files may fail to open in some Windows environments. Most often, users report that the CHM file opens and displays the navigation (table of contents) in the left pane, but the right pane is empty or shows a warning message. If this happens to you:

1. Download the CHM and store it to a local drive on your PC. Do not store it on a network drive.
2. Right-click on the CHM file in Windows Explorer and select Properties.
3. On the General tab of the Properties dialog, click Unblock, then click OK.

Visit our CHM troubleshooting page to resolve other, less-commonly reported CHM issues.