Every once and a while I have come across a .chm file that I just cannot read. It opens fine and I can traverse through the menu on the left hand pane. The issue is that every page on in the right hand pane shows “This program cannot display the webpage”. I have never been able to figure out a sure fire way to resolve the issue.

Not only have I seen this issue with .chm files I have downloaded but in .chm files I have created and sent to colleagues. The .chm files work great on my machine but will not display correctly on others machines.

It looks like Windows XP automatically blocks files you download from an external source. You can “Unblock” the file by opening the file properties and clicking the “Unblock” button beside the security section of the general tab. (This option only seems to be displayed if the file is blocked).

Voila! The CHM files work great.