I'm currently evaluating InstallShield 2016 (Premier); and I'm trying to create a QuickPatch project which updates a few files in an install. The starting point is the MSI from the original install.

The original MSI creates some registry keys and values, but some of those values aren't hard-wired, they're based on variables whose values are set while you go through the installation wizard: a dialog prompts you to enter a value, and the registry value in question is set to whatever you type in.

The QuickPatch project picks up all of the registry keys that the original MSI sets, and the default is to set them to the same value that the MSI would... but in this case the value that the MSI would set it to is the value of a variable which *isn't set* unless you've actually run the MSI! So, when the quickpatch update.exe is run, the registry value ends up being changed to a blank string. What I want it to do is to leave it unchanged. There doesn't seem to be any way to make the QuickPath project ignore the registry key altogether - you can modify it, delete it, or set it to the MSI value, but I can't find any way to tell it "just forget about that key entirely".

How does one do this?