The case of the mysteriously hanging InstallShield
sp <foobarcom> Wednesday, October 11 2006 14:35.38 CDT


Ever since I reinstalled Windows a while ago most InstallShield Setup programs refused to work. They just froze when I started them and nothing happened. According to the Internet there are approximately a million reasons that cause this behaviour. I tried a few solutions but none of them worked. It was time to whip out good old OllyDbg.

The cause of the problem was quickly located. For whatever reason InstallShield broadcasts user-defined messages using SendMessage to all active windows. Heres a screenshot of the situation in OllyDbg.

Due to the nature of SendMessage the setup program wont continue until all window procedures have processed that message. Apparently theres (at least) one window on my system which does not process that message. I shut down the active processes and tried to run an InstallShield setup again. I kept doing this until I found the culprit. Of course it was the very last program I shut down which didnt process the message: Kerio Personal Firewall. I suspect its KPF at least. Setups dont work when Kerio is active and they work when its not.

I havent looked into the exact reasons why InstallShield decides to broadcast window messages all across the system. I suspect its because the one-file setup programs you download from the Internet extract the real setup and then execute it and the two setup processes (which are basically front-end and back-end of the installation) have to communicate. Maybe thats totally wrong but I think its a good guess. As a side-note I want to mention that InstallShield follows the proper procedure of registering a unique window message ID using RegisterWindowMessage. The blame does not rest on them.

So far I didnt look into fixing the problem permanently. Right now Im happy that I can install what I want using a small work-around. Im just wondering what exactly the difference between my old system and my new system is that caused the problems. Maybe Im using a newer version of Kerio now that introduced the behaviour. All other things are the same on both systems as far as I can tell.

The moral of the story is that Im glad that I know how to use OllyDbg. Otherwise I probably wouldnt have figured that one out so quickly. In the worst case Id have reinstalled my system once again.



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Posted: Wednesday, December 31 1969 18:00.00 CST