Why is the .chm help not working? I always get the message “Navigation to the webpage was canceled”.

The following message is displayed if the chm file is located on a network drive:
"Navigation to the webpage was canceled
What you can try: Retype the address"

This error occurs because some Microsoft security updates are blocking the contents of chm files when opened from a network drive.

There are 3 ways to fix this.

1. Windows implemented a solution for Windows 7 and Windows Server 2008.
Open the context menu by a right click on the chm file and select Properties.
In the "<name>.chm Properties" dialog box you have to select the check box named "Unblock". Confirm your changes with the OK button.

2. Open the registry editor (Start - Run - regedit) and go to HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/HTMLHelp/1.x/ItssRestrictions. If ItssRestrictions does not exist you have to create it.
Right click on ItssRestrictions, click on New and select "DWORD Value". Enter MaxAllowedZone as a name. Right click on MaxAllowedZone and click Modify. Set the value to 1 (= Local Intranet Zone).

3. If the previous methods are not working you have to copy the chm file from the network drive to a local drive.