Hi there,

I have a computer that cannot open a chm file that is located on a server. (it is part of a program, and you access it by clicking on the F1 for help)

If you browse to the file on the server and double click it you get the message "action cancelled unable to link to webpage etc" you can copy the file locally and open it fine. I have checked the user's permissions and they are fine, no-one else is having the problem, just this computer.

I know this is not exactly web dev, but if anyone will know you will.

I think the problem is a result of a security update Microsoft made a while back which restricts opening certain files on the local network which could run malicious code. Here is a link to a description of the problem: http://support.microsoft.com/kb/896358

The fix is to modify your registry to relax the security for accessing files on your network. There are several examples on how to relax those settings on the page above. Many require you to know which applicatins and types of files need to be un-restricted. The following will relax restrictions for your entire internal network.

REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp]
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\HHRestrictions]
"MaxAllowedZone"=dword:00000001
"EnableFrameNavigationInSafeMode"=dword:00000001

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

You use this at your own risk. However, this is the approach my company initially took internally and with our customers before we were able to deploy a more refined approach. Just copy and past the above into notepad and save as a .reg file, then run it.

Michael J

Thanks for that Michael, that worked a treat!!!