Allow viewing of CHM files across the network

Microsoft have released a patch to fix a vulnerability in HTML Help (MS05-026 (896358)). This patch disables the ability to view Compressed HTML (CHM) files placed on a remote computer, and one will get the following error message:

*this page cannot be displayed

Action cancelled.

Navigation to the webpage was cancelled.*

To view the CHM file one have to download the CHM file to the local computer to view it properly. Even if having downloaded the CHM file to the local computer, then one might experience a security warning when opening the CHM file. It is is possible to unblock file and avoid the warning.

If in an environment where the computers (and the users) in the Intranet Zone can be trusted, then one configure the HTML Help viewer to allow viewing of CHM files placed on a local network drive. Create the following registry key:

[HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \HTMLHelp \1.x \ItssRestrictions]
MaxAllowedZone = 1

More Info MS KB892675
More Info MS KB896054