cannot open the _isres.dll file

[Mark_Lim]

I have a Install Shield 2008 Premier Edition for Windows
I tried to open the _isres.dll file with vs6, vs2005 and resource hacker to add some images for a custom SdOptionsButtons dialog. But I couldn't open it. I just got some error messages as follows.

When I tried it in vs6,


When I tried it in vs2005


When I tried it in resource hacker


I wasn't able to find any posts related to my problem.
How can I open and modify it?
Any help you could provide would be appreciated.

[Mark_Lim]

any idea..?

[joshstechnij]

The InstallScript resource DLLs are compressed to cut down on the size overhead for the engine. You can get the uncompressed versions from the following thread:
http://community.acresso.com/showthread.php?t=183580