I'm not aware of any way to prevent a specific executable program from being executed via the base Windows APIs. I think the only way to do it would be to replace the Kernel32.dll (and equivalent 64-bit library) with copies that have customized versions of the CreateProcess routine.
Unfortunately that only works for about 30 minutes before a separate (necessary application) re-runs it. I had been disabling the security rights to the executable, but now they are completely replacing the .exe, and that in turn re-enables their "screen spam".
Not sure what more I can add to get a solution... but an admin email suggests I post something or forget about getting an answer from this forum
I should note, that other boards have suggested that that I merely change the permissions on the security of the exe or dll files. That used to work until they revised the "auto updater" to spam "you must restart your PC" messages so they could replace the files I blocked.