Problem when view CHM files over LAN

Problem when view CHM files over LAN

When you view files which use HTML Help featues (for instance, the chm file format) from a remote location, you can open the file but the content won’t show up as the example figure below.

I try to open a remote chm file from bkkvirtual01 pc.
The file was opened, but the content was unavailable and show error message
“Action canceled
Internet Explorer was enable to link to the Web page you
requested. The page might be temporaily unavailable.”

Can't view a remote chm file

This is an expected effect from security updates (896358 and 890175) to prevent threats from HTML Help that could allow remote code execution(more information at microsoft knowledgebase MS05-026 and MS05-001)


If you are on the network which can be trusted and secure, you can try to lower the security restrictions for the Local intranet zone to allow chm files to be open remotely by modify the windows registry.

The solution belows will change key “MaxAllowedZone” in Windows Registry to ‘1’ to allow HTML Help features for Local Machine Zone and Local intranet zone.

Solution 1: Manually create key on Windows Registry

  1. Open Registry Editor.
  2. Expand to My Computer\HKEY_LOCAL\MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x
  3. Create new Key “ItssRestrictions” under 1.x. if you already have this key, skip this step.
  4. Add new REG_ DWORD as “MaxAllowedZone” and assign value ‘1’.
  5. Add key to Windows Registry

Solution 2: Execute .reg file

Copy the code below, paste into text editor, save as .reg file and execute it.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions] “MaxAllowedZone”=dword:00000001

Add key on Windows Registry using text file

After add the registry key, try open the file again, now I can open a remote CHM file.
Open a remote CHM file

For more information, visit Microsoft Knowledge base at 892675


  1. Oil January 3, 2008
  2. subra January 7, 2008
  3. linglom January 7, 2008
  4. rjt February 9, 2008
  5. linglom February 10, 2008
  6. Thund3rstruck November 3, 2009

Leave a Reply