Need help with Axonet's Upgrade Code plug-in

[Chris Miller]

I have a app setup written with InstallAware 7 and it needs to uninstall a previous version of the app. The previous version used Wise For Windows to author the setup. I'm using Axonet's Upgrade Code plug-in to get the product code from the update code. I have used that plug-in with other pojects of this nature and it worked great. This project, it can't find the product code on some XP boxes. Other machines work fine, but I have two where it fails 100% of the time.

I have verified that I have the right upgrade code from both the Wise .wsi file and the .msi file. I don't have the source for the upgrade plug-in, what is the logic that it used to find the product code from the upgrade code?