How to get Windows to stop trying to install MSI file

Question

We have a Windows Server 2019 VM used primarily to run IIS apps. On Saturday, the machine was rebooted, and started spewing MSI errors.
Product: Portal v1.6.77 -- This setup requires Internet Information Server 5.1 or higher and Windows XP or higher. This setup cannot be installed on Windows 2000. Please install Internet Information Server or a newer operating system and run this setup again.

This was probably because it wants Windows Installer 3.1. I fired up one of our last copies of Visual Studio 2010, updated the installer and rebuilt the package. After uninstalling the old version, and installing the new, we get a different error.
Product: Portal v1.6.77 -- Unable to install because a newer version of this product is already installed.
While it's nice that it can't install an older version over a newer version, we'd really like it to stop, especially because it's trying every several minutes. How do we get it to stop?

Answer 1

If you hacked away at the .msi to modify the installer, then you're pretty much on your own to troubleshoot problems. Both the installation process and the functionality of the app itself. The installer is telling you that "we don't support this OS".

Why don't you contact whoever supports/develops Portal v1.6.77 and get an updated version that they have documented to support IIS 10 on Server 2019.

Does anything show up in add/remove programs? Can you uninstall it?

As far as "where is this coming from?" you could start with some tools from https://Sysinternals.com.

The autoruns utility will report on all settings within Windows where a process could get launched at boot time. Services, scheduled tasks, registry keys, etc. You will need to run that and look for the setup or msi name in one of those entries.

If you can't find anything, then try Process Explorer. The process list will be indented by parent/child process. You can click and hold on the target icon (next to the binoculars icon) on the menu and drag and drop it on the installer windows (if there is one). Look to see the command line that launches the install process and also its parent processes. Do you see anything that might indicate how it was launched?