CHM help files don’t display their content
Trying to view a chm help file and getting something like “This program cannot display the webpage” or “Page Cannot Be Displayed” or this sort of thing …
There are plenty of solutions on the web about unblocking chm files in Vista etc but here is a curly one that can catch you out – if the path or file name of the .chm contains the “#” character then you have a problem. The solution is to rename it, removing the # character.
See http://support.microsoft.com/kb/319247 for details.
I hope this saves you the considerable amount of time it took me to find this.