Windows Server 2019 – How to Copy Fonts to C:\Windows\Fonts Using GPO

It's my suspicion that either

1. Something in this plugin is angering Outlook, or, more likely
2. Something is causing this installation to roll back. (Antivirus? Something else that polices Outlook configuration?)

I'm assuming, since it's an Outlook plugin, that it has to run as the user.

I would experiment with a login script that checks for the installed plugin, and, if it's not there, runs a msiexec /i file.msi /quiet to see what happens. Yes, I know that's what the GPO is doing. As a test, you could run it as a login script with logging (msiexec /i Example.msi /Lime c:\temp\logfile.txt) so you'd have a record of any errors. That should at least help you debug.

Eh, I finally gave up an just created a GPP which puts a shortcut "%ProgramFiles%\Internet Explorer\iexplore -k" in Startup.

It works great. Not sure why using Scheduled Tasks has this problem with the Taskbar retaining focus.