Fixing "CHM can not be displayed errors" due to a Microsoft security patch

Because of a security patch for Windows, CHM files located on a remote folder accessed via UNC path will fail to open. The security setting can be relaxed by modifying the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions setting MaxAllowedZone to dword:00000002 or if you trust me enough, download this file to your windows xp desktop and double click it.