MSIZAP is REALLY useful in situations where the MSI database in the registry gets corrupted to the point where:
-You cannot uninstall existing bad installation
-you cannot reinstall over a bad installation (Error, MSI package already installed)
MSIZAP makes the MSI Database forget the MSI package was ever installed but leaves the application files intact. Afterwards, you should be able to reinstall with the MSI.
I’m amazed the author found a MS Download link for MSIZAP.
You are right, the usage of MSI Zap is not a joke, some experience is recommended.
I used to use it for every MSI uninstallation with no problem, but be advised that with multiple MSI dependant software, like AutoCAD / Revit some problems may occur.